Method and apparatus for launching a wave mode that mitigates interference

ABSTRACT

Aspects of the subject disclosure may include, for example, a system that performs operations including receiving first electromagnetic waves on an outer surface of a transmission medium, detecting a degradation of a signal quality of the first electromagnetic waves due to first electric fields of the first electromagnetic waves inducing first currents in an obstruction disposed on the outer surface of the transmission medium, and generating second electromagnetic waves having second electric fields that induce second currents in the obstruction that are lower in magnitude than the first currents, the electromagnetic waves having a cutoff frequency. Other embodiments are disclosed.

FIELD OF THE DISCLOSURE

The subject disclosure relates to communications via microwavetransmission in a communication network.

BACKGROUND

As smart phones and other portable devices increasingly becomeubiquitous, and data usage increases, macrocell base station devices andexisting wireless infrastructure in turn require higher bandwidthcapability in order to address the increased demand. To provideadditional mobile bandwidth, small cell deployment is being pursued,with microcells and picocells providing coverage for much smaller areasthan traditional macrocells.

In addition, most homes and businesses have grown to rely on broadbanddata access for services such as voice, video and Internet browsing,etc. Broadband access networks include satellite, 4G or 5G wireless,power line communication, fiber, cable, and telephone networks.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference will now be made to the accompanying drawings, which are notnecessarily drawn to scale, and wherein:

FIG. 1 is a block diagram illustrating an example, non-limitingembodiment of a guided-wave communications system in accordance withvarious aspects described herein.

FIG. 2 is a block diagram illustrating an example, non-limitingembodiment of a transmission device in accordance with various aspectsdescribed herein.

FIG. 3 is a graphical diagram illustrating an example, non-limitingembodiment of an electromagnetic field distribution in accordance withvarious aspects described herein.

FIG. 4 is a graphical diagram illustrating an example, non-limitingembodiment of an electromagnetic field distribution in accordance withvarious aspects described herein.

FIG. 5A is a graphical diagram illustrating an example, non-limitingembodiment of a frequency response in accordance with various aspectsdescribed herein.

FIG. 5B is a graphical diagram illustrating example, non-limitingembodiments of a longitudinal cross-section of an insulated wiredepicting fields of guided electromagnetic waves at various operatingfrequencies in accordance with various aspects described herein.

FIG. 6 is a graphical diagram illustrating an example, non-limitingembodiment of an electromagnetic field distribution in accordance withvarious aspects described herein.

FIG. 7 is a block diagram illustrating an example, non-limitingembodiment of an arc coupler in accordance with various aspectsdescribed herein.

FIG. 8 is a block diagram illustrating an example, non-limitingembodiment of an arc coupler in accordance with various aspectsdescribed herein.

FIG. 9A is a block diagram illustrating an example, non-limitingembodiment of a stub coupler in accordance with various aspectsdescribed herein.

FIG. 9B is a diagram illustrating an example, non-limiting embodiment ofan electromagnetic distribution in accordance with various aspectsdescribed herein.

FIGS. 10A and 10B are block diagrams illustrating example, non-limitingembodiments of couplers and transceivers in accordance with variousaspects described herein.

FIG. 11 is a block diagram illustrating an example, non-limitingembodiment of a dual stub coupler in accordance with various aspectsdescribed herein.

FIG. 12 is a block diagram illustrating an example, non-limitingembodiment of a repeater system in accordance with various aspectsdescribed herein.

FIG. 13 illustrates a block diagram illustrating an example,non-limiting embodiment of a bidirectional repeater in accordance withvarious aspects described herein.

FIG. 14 is a block diagram illustrating an example, non-limitingembodiment of a waveguide system in accordance with various aspectsdescribed herein.

FIG. 15 is a block diagram illustrating an example, non-limitingembodiment of a guided-wave communications system in accordance withvarious aspects described herein.

FIGS. 16A & 16B are block diagrams illustrating an example, non-limitingembodiment of a system for managing a power grid communication system inaccordance with various aspects described herein.

FIG. 17A illustrates a flow diagram of an example, non-limitingembodiment of a method for detecting and mitigating disturbancesoccurring in a communication network of the system of FIGS. 16A and 16B.

FIG. 17B illustrates a flow diagram of an example, non-limitingembodiment of a method for detecting and mitigating disturbancesoccurring in a communication network of the system of FIGS. 16A and 16B.

FIGS. 18A, 18B, and 18C are block diagrams illustrating example,non-limiting embodiment of a transmission medium for propagating guidedelectromagnetic waves.

FIG. 18D is a block diagram illustrating an example, non-limitingembodiment of bundled transmission media in accordance with variousaspects described herein.

FIG. 18E is a block diagram illustrating an example, non-limitingembodiment of a plot depicting cross-talk between first and secondtransmission mediums of the bundled transmission media of FIG. 18D inaccordance with various aspects described herein.

FIG. 18F is a block diagram illustrating an example, non-limitingembodiment of bundled transmission media to mitigate cross-talk inaccordance with various aspects described herein.

FIGS. 18G and 18H are block diagrams illustrating example, non-limitingembodiments of a transmission medium with an inner waveguide inaccordance with various aspects described herein.

FIGS. 18I and 18J are block diagrams illustrating example, non-limitingembodiments of connector configurations that can be used with thetransmission medium of FIG. 18A, 18B, or 18C.

FIG. 18K is a block diagram illustrating example, non-limitingembodiments of transmission mediums for propagating guidedelectromagnetic waves.

FIG. 18L is a block diagram illustrating example, non-limitingembodiments of bundled transmission media to mitigate cross-talk inaccordance with various aspects described herein.

FIG. 18M is a block diagram illustrating an example, non-limitingembodiment of exposed stubs from the bundled transmission media for useas antennas in accordance with various aspects described herein.

FIGS. 18N, 18O, 18P, 18Q, 18R, 18S, 18T, 18U, 18V and 18W are blockdiagrams illustrating example, non-limiting embodiments of a waveguidedevice for transmitting or receiving electromagnetic waves in accordancewith various aspects described herein.

FIGS. 19A and 19B are block diagrams illustrating example, non-limitingembodiments of the transmission medium of FIG. 18A used for inducingguided electromagnetic waves on power lines supported by utility poles.

FIG. 19C is a block diagram of an example, non-limiting embodiment of acommunication network in accordance with various aspects describedherein.

FIG. 20A illustrates a flow diagram of an example, non-limitingembodiment of a method for transmitting downlink signals.

FIG. 20B illustrates a flow diagram of an example, non-limitingembodiment of a method for transmitting uplink signals.

FIG. 20C illustrates a flow diagram of an example, non-limitingembodiment of a method for inducing electromagnetic waves on atransmission medium.

FIG. 20D illustrates a flow diagram of an example, non-limitingembodiment of a method for receiving electromagnetic waves from atransmission medium.

FIG. 20E illustrates a flow diagram of an example, non-limitingembodiment of a method for inducing electromagnetic waves on atransmission medium.

FIG. 20F illustrates a flow diagram of an example, non-limitingembodiment of a method for receiving electromagnetic waves from atransmission medium.

FIG. 20G illustrates a flow diagram of an example, non-limitingembodiment of a method for detecting and mitigating disturbancesoccurring in a communication network.

FIG. 20H is a block diagram illustrating an example, non-limitingembodiment of an alignment of fields of an electromagnetic wave tomitigate propagation losses due to water accumulation on a transmissionmedium in accordance with various aspects described herein.

FIGS. 20I and 20J are block diagrams illustrating example, non-limitingembodiments of electric field intensities of different electromagneticwaves propagating in the cable illustrated in FIG. 20H in accordancewith various aspects described herein.

FIG. 20K is a block diagram illustrating an example, non-limitingembodiment of electric fields of a Goubau wave in accordance withvarious aspects described herein.

FIG. 20L is a block diagram illustrating an example, non-limitingembodiment of electric fields of a hybrid wave in accordance withvarious aspects described herein.

FIG. 20M is a block diagram illustrating an example, non-limitingembodiment of electric field characteristics of a hybrid wave versus aGoubau wave in accordance with various aspects described herein.

FIG. 20N is a block diagram illustrating an example, non-limitingembodiment of mode sizes of hybrid waves at various operatingfrequencies in accordance with various aspects described herein.

FIGS. 21A and 21B are block diagrams illustrating example, non-limitingembodiments of a waveguide device for launching hybrid waves inaccordance with various aspects described herein.

FIG. 22 is a block diagram illustrating an example, non-limitingembodiment of a hybrid wave launched by the waveguide device of FIGS.21A and 21B in accordance with various aspects described herein.

FIG. 23 is a block diagram of an example, non-limiting embodiment of acomputing environment in accordance with various aspects describedherein.

FIG. 24 is a block diagram of an example, non-limiting embodiment of amobile network platform in accordance with various aspects describedherein.

FIG. 25 is a block diagram of an example, non-limiting embodiment of acommunication device in accordance with various aspects describedherein.

DETAILED DESCRIPTION

One or more embodiments are now described with reference to thedrawings, wherein like reference numerals are used to refer to likeelements throughout. In the following description, for purposes ofexplanation, numerous details are set forth in order to provide athorough understanding of the various embodiments. It is evident,however, that the various embodiments can be practiced without thesedetails (and without applying to any particular networked environment orstandard).

In an embodiment, a guided wave communication system is presented forsending and receiving communication signals such as data or othersignaling via guided electromagnetic waves. The guided electromagneticwaves include, for example, surface waves or other electromagnetic wavesthat are bound to or guided by a transmission medium. It will beappreciated that a variety of transmission media can be utilized withguided wave communications without departing from example embodiments.Examples of such transmission media can include one or more of thefollowing, either alone or in one or more combinations: wires, whetherinsulated or not, and whether single-stranded or multi-stranded;conductors of other shapes or configurations including wire bundles,cables, rods, rails, pipes; non-conductors such as dielectric pipes,rods, rails, or other dielectric members; combinations of conductors anddielectric materials; or other guided wave transmission media.

The inducement of guided electromagnetic waves on a transmission mediumcan be independent of any electrical potential, charge or current thatis injected or otherwise transmitted through the transmission medium aspart of an electrical circuit. For example, in the case where thetransmission medium is a wire, it is to be appreciated that while asmall current in the wire may be formed in response to the propagationof the guided waves along the wire, this can be due to the propagationof the electromagnetic wave along the wire surface, and is not formed inresponse to electrical potential, charge or current that is injectedinto the wire as part of an electrical circuit. The electromagneticwaves traveling on the wire therefore do not require a circuit topropagate along the wire surface. The wire therefore is a single wiretransmission line that is not part of a circuit. Also, in someembodiments, a wire is not necessary, and the electromagnetic waves canpropagate along a single line transmission medium that is not a wire.

More generally, “guided electromagnetic waves” or “guided waves” asdescribed by the subject disclosure are affected by the presence of aphysical object that is at least a part of the transmission medium(e.g., a bare wire or other conductor, a dielectric, an insulated wire,a conduit or other hollow element, a bundle of insulated wires that iscoated, covered or surrounded by a dielectric or insulator or other wirebundle, or another form of solid, liquid or otherwise non-gaseoustransmission medium) so as to be at least partially bound to or guidedby the physical object and so as to propagate along a transmission pathof the physical object. Such a physical object can operate as at least apart of a transmission medium that guides, by way of an interface of thetransmission medium (e.g., an outer surface, inner surface, an interiorportion between the outer and the inner surfaces or other boundarybetween elements of the transmission medium), the propagation of guidedelectromagnetic waves, which in turn can carry energy, data and/or othersignals along the transmission path from a sending device to a receivingdevice.

Unlike free space propagation of wireless signals such as unguided (orunbounded) electromagnetic waves that decrease in intensity inversely bythe square of the distance traveled by the unguided electromagneticwaves, guided electromagnetic waves can propagate along a transmissionmedium with less loss in magnitude per unit distance than experienced byunguided electromagnetic waves.

Unlike electrical signals, guided electromagnetic waves can propagatefrom a sending device to a receiving device without requiring a separateelectrical return path between the sending device and the receivingdevice. As a consequence, guided electromagnetic waves can propagatefrom a sending device to a receiving device along a transmission mediumhaving no conductive components (e.g., a dielectric strip), or via atransmission medium having no more than a single conductor (e.g., asingle bare wire or insulated wire). Even if a transmission mediumincludes one or more conductive components and the guidedelectromagnetic waves propagating along the transmission medium generatecurrents that flow in the one or more conductive components in adirection of the guided electromagnetic waves, such guidedelectromagnetic waves can propagate along the transmission medium from asending device to a receiving device without requiring a flow ofopposing currents on an electrical return path between the sendingdevice and the receiving device.

In a non-limiting illustration, consider electrical systems thattransmit and receive electrical signals between sending and receivingdevices by way of conductive media. Such systems generally rely onelectrically separate forward and return paths. For instance, consider acoaxial cable having a center conductor and a ground shield that areseparated by an insulator. Typically, in an electrical system a firstterminal of a sending (or receiving) device can be connected to thecenter conductor, and a second terminal of the sending (or receiving)device can be connected to the ground shield. If the sending deviceinjects an electrical signal in the center conductor via the firstterminal, the electrical signal will propagate along the centerconductor causing forward currents in the center conductor, and returncurrents in the ground shield. The same conditions apply for a twoterminal receiving device.

In contrast, consider a guided wave communication system such asdescribed in the subject disclosure, which can utilize differentembodiments of a transmission medium (including among others a coaxialcable) for transmitting and receiving guided electromagnetic waveswithout an electrical return path. In one embodiment, for example, theguided wave communication system of the subject disclosure can beconfigured to induce guided electromagnetic waves that propagate alongan outer surface of a coaxial cable. Although the guided electromagneticwaves will cause forward currents on the ground shield, the guidedelectromagnetic waves do not require return currents to enable theguided electromagnetic waves to propagate along the outer surface of thecoaxial cable. The same can be said of other transmission media used bya guided wave communication system for the transmission and reception ofguided electromagnetic waves. For example, guided electromagnetic wavesinduced by the guided wave communication system on an outer surface of abare wire, or an insulated wire can propagate along the bare wire or theinsulated bare wire without an electrical return path.

Consequently, electrical systems that require two or more conductors forcarrying forward and reverse currents on separate conductors to enablethe propagation of electrical signals injected by a sending device aredistinct from guided wave systems that induce guided electromagneticwaves on an interface of a transmission medium without the need of anelectrical return path to enable the propagation of the guidedelectromagnetic waves along the interface of the transmission medium.

It is further noted that guided electromagnetic waves as described inthe subject disclosure can have an electromagnetic field structure thatlies primarily or substantially outside of a transmission medium so asto be bound to or guided by the transmission medium and so as topropagate non-trivial distances on or along an outer surface of thetransmission medium. In other embodiments, guided electromagnetic wavescan have an electromagnetic field structure that lies primarily orsubstantially inside a transmission medium so as to be bound to orguided by the transmission medium and so as to propagate non-trivialdistances within the transmission medium. In other embodiments, guidedelectromagnetic waves can have an electromagnetic field structure thatlies partially inside and partially outside a transmission medium so asto be bound to or guided by the transmission medium and so as topropagate non-trivial distances along the transmission medium. Thedesired electronic field structure in an embodiment may vary based upona variety of factors, including the desired transmission distance, thecharacteristics of the transmission medium itself, and environmentalconditions/characteristics outside of the transmission medium (e.g.,presence of rain, fog, atmospheric conditions, etc.).

Various embodiments described herein relate to coupling devices, thatcan be referred to as “waveguide coupling devices”, “waveguide couplers”or more simply as “couplers”, “coupling devices” or “launchers” forlaunching and/or extracting guided electromagnetic waves to and from atransmission medium at millimeter-wave frequencies (e.g., 30 to 300GHz), wherein the wavelength can be small compared to one or moredimensions of the coupling device and/or the transmission medium such asthe circumference of a wire or other cross sectional dimension, or lowermicrowave frequencies such as 300 MHz to 30 GHz. Transmissions can begenerated to propagate as waves guided by a coupling device, such as: astrip, arc or other length of dielectric material; a horn, monopole,rod, slot or other antenna; an array of antennas; a magnetic resonantcavity, or other resonant coupler; a coil, a strip line, a waveguide orother coupling device. In operation, the coupling device receives anelectromagnetic wave from a transmitter or transmission medium. Theelectromagnetic field structure of the electromagnetic wave can becarried inside the coupling device, outside the coupling device or somecombination thereof. When the coupling device is in close proximity to atransmission medium, at least a portion of an electromagnetic wavecouples to or is bound to the transmission medium, and continues topropagate as guided electromagnetic waves. In a reciprocal fashion, acoupling device can extract guided waves from a transmission medium andtransfer these electromagnetic waves to a receiver.

According to an example embodiment, a surface wave is a type of guidedwave that is guided by a surface of a transmission medium, such as anexterior or outer surface of the wire, or another surface of the wirethat is adjacent to or exposed to another type of medium havingdifferent properties (e.g., dielectric properties). Indeed, in anexample embodiment, a surface of the wire that guides a surface wave canrepresent a transitional surface between two different types of media.For example, in the case of a bare or uninsulated wire, the surface ofthe wire can be the outer or exterior conductive surface of the bare oruninsulated wire that is exposed to air or free space. As anotherexample, in the case of insulated wire, the surface of the wire can bethe conductive portion of the wire that meets the insulator portion ofthe wire, or can otherwise be the insulator surface of the wire that isexposed to air or free space, or can otherwise be any material regionbetween the insulator surface of the wire and the conductive portion ofthe wire that meets the insulator portion of the wire, depending uponthe relative differences in the properties (e.g., dielectric properties)of the insulator, air, and/or the conductor and further dependent on thefrequency and propagation mode or modes of the guided wave.

According to an example embodiment, the term “about” a wire or othertransmission medium used in conjunction with a guided wave can includefundamental guided wave propagation modes such as a guided waves havinga circular or substantially circular field distribution, a symmetricalelectromagnetic field distribution (e.g., electric field, magneticfield, electromagnetic field, etc.) or other fundamental mode pattern atleast partially around a wire or other transmission medium. In addition,when a guided wave propagates “about” a wire or other transmissionmedium, it can do so according to a guided wave propagation mode thatincludes not only the fundamental wave propagation modes (e.g., zeroorder modes), but additionally or alternatively non-fundamental wavepropagation modes such as higher-order guided wave modes (e.g., 1^(st)order modes, 2^(nd) order modes, etc.), asymmetrical modes and/or otherguided (e.g., surface) waves that have non-circular field distributionsaround a wire or other transmission medium. As used herein, the term“guided wave mode” refers to a guided wave propagation mode of atransmission medium, coupling device or other system component of aguided wave communication system.

For example, such non-circular field distributions can be unilateral ormulti-lateral with one or more axial lobes characterized by relativelyhigher field strength and/or one or more nulls or null regionscharacterized by relatively low-field strength, zero-field strength orsubstantially zero-field strength. Further, the field distribution canotherwise vary as a function of azimuthal orientation around the wiresuch that one or more angular regions around the wire have an electricor magnetic field strength (or combination thereof) that is higher thanone or more other angular regions of azimuthal orientation, according toan example embodiment. It will be appreciated that the relativeorientations or positions of the guided wave higher order modes orasymmetrical modes can vary as the guided wave travels along the wire.

As used herein, the term “millimeter-wave” can refer to electromagneticwaves/signals that fall within the “millimeter-wave frequency band” of30 GHz to 300 GHz. The term “microwave” can refer to electromagneticwaves/signals that fall within a “microwave frequency band” of 300 MHzto 300 GHz. The term “radio frequency” or “RF” can refer toelectromagnetic waves/signals that fall within the “radio frequencyband” of 10 kHz to 1 THz. It is appreciated that wireless signals,electrical signals, and guided electromagnetic waves as described in thesubject disclosure can be configured to operate at any desirablefrequency range, such as, for example, at frequencies within, above orbelow millimeter-wave and/or microwave frequency bands. In particular,when a coupling device or transmission medium includes a conductiveelement, the frequency of the guided electromagnetic waves that arecarried by the coupling device and/or propagate along the transmissionmedium can be below the mean collision frequency of the electrons in theconductive element. Further, the frequency of the guided electromagneticwaves that are carried by the coupling device and/or propagate along thetransmission medium can be a non-optical frequency, e.g., a radiofrequency below the range of optical frequencies that begins at 1 THz.

As used herein, the term “antenna” can refer to a device that is part ofa transmitting or receiving system to transmit/radiate or receivewireless signals.

In accordance with one or more embodiments, a waveguide system caninclude a launcher that facilitates generation of electromagnetic waves,and a processor coupled to the launcher, wherein the processorfacilitates performance of operations. The operations can includeobtaining one or more operational parameters for configuring thelauncher to generate electromagnetic waves having electric fields thatare not longitudinally aligned with an obstruction disposed on an outersurface of a transmission medium and that extend outside theobstruction, the electromagnetic waves having a cutoff frequency, andthe cutoff frequency comprising a non-optical frequency, and directingthe launcher to launch the electromagnetic waves according to the one ormore operational parameters, and to induce the electromagnetic waves onthe outer surface of the transmission medium.

In accordance with one or more embodiments, a method can includedetermining, by a waveguide system, one or more operational parametersfor generating electromagnetic waves having electric fields that are notpolarized longitudinally in a first region above an outer surface of atransmission medium, and that extend into a second region located abovethe first region, generating, by the waveguide system, theelectromagnetic waves according to the one or more operationalparameters, the electromagnetic waves having a cutoff frequency, andinducing, by the waveguide system, the electromagnetic waves on theouter surface of the transmission medium.

In accordance with one or more embodiments, a method can includereceiving, by a waveguide system, first electromagnetic waves on anouter surface of a transmission medium, detecting, by the waveguidesystem, a degradation of a signal quality of the first electromagneticwaves due to first electric fields of the first electromagnetic wavesinducing first currents in an obstruction disposed on the outer surfaceof the transmission medium, and generating, by the waveguide system,second electromagnetic waves having second electric fields that inducesecond currents in the obstruction that are lower in magnitude than thefirst currents, the electromagnetic waves having a cutoff frequency.

Referring now to FIG. 1, a block diagram 100 illustrating an example,non-limiting embodiment of a guided wave communications system is shown.In operation, a transmission device 101 receives one or morecommunication signals 110 from a communication network or othercommunications device that includes data and generates guided waves 120to convey the data via the transmission medium 125 to the transmissiondevice 102. The transmission device 102 receives the guided waves 120and converts them to communication signals 112 that include the data fortransmission to a communications network or other communications device.The guided waves 120 can be modulated to convey data via a modulationtechnique such as phase shift keying, frequency shift keying, quadratureamplitude modulation, amplitude modulation, multi-carrier modulationsuch as orthogonal frequency division multiplexing and via multipleaccess techniques such as frequency division multiplexing, time divisionmultiplexing, code division multiplexing, multiplexing via differingwave propagation modes and via other modulation and access strategies.

The communication network or networks can include a wirelesscommunication network such as a mobile data network, a cellular voiceand data network, a wireless local area network (e.g., WiFi or an 802.xxnetwork), a satellite communications network, a personal area network orother wireless network. The communication network or networks can alsoinclude a wired communication network such as a telephone network, anEthernet network, a local area network, a wide area network such as theInternet, a broadband access network, a cable network, a fiber opticnetwork, or other wired network. The communication devices can include anetwork edge device, bridge device or home gateway, a set-top box,broadband modem, telephone adapter, access point, base station, or otherfixed communication device, a mobile communication device such as anautomotive gateway or automobile, laptop computer, tablet, smartphone,cellular telephone, or other communication device.

In an example embodiment, the guided wave communication system 100 canoperate in a bi-directional fashion where transmission device 102receives one or more communication signals 112 from a communicationnetwork or device that includes other data and generates guided waves122 to convey the other data via the transmission medium 125 to thetransmission device 101. In this mode of operation, the transmissiondevice 101 receives the guided waves 122 and converts them tocommunication signals 110 that include the other data for transmissionto a communications network or device. The guided waves 122 can bemodulated to convey data via a modulation technique such as phase shiftkeying, frequency shift keying, quadrature amplitude modulation,amplitude modulation, multi-carrier modulation such as orthogonalfrequency division multiplexing and via multiple access techniques suchas frequency division multiplexing, time division multiplexing, codedivision multiplexing, multiplexing via differing wave propagation modesand via other modulation and access strategies.

The transmission medium 125 can include a cable having at least oneinner portion surrounded by a dielectric material such as an insulatoror other dielectric cover, coating or other dielectric material, thedielectric material having an outer surface and a correspondingcircumference. In an example embodiment, the transmission medium 125operates as a single-wire transmission line to guide the transmission ofan electromagnetic wave. When the transmission medium 125 is implementedas a single wire transmission system, it can include a wire. The wirecan be insulated or uninsulated, and single-stranded or multi-stranded(e.g., braided). In other embodiments, the transmission medium 125 cancontain conductors of other shapes or configurations including wirebundles, cables, rods, rails, pipes. In addition, the transmissionmedium 125 can include non-conductors such as dielectric pipes, rods,rails, or other dielectric members; combinations of conductors anddielectric materials, conductors without dielectric materials or otherguided wave transmission media. It should be noted that the transmissionmedium 125 can otherwise include any of the transmission mediapreviously discussed.

Further, as previously discussed, the guided waves 120 and 122 can becontrasted with radio transmissions over free space/air or conventionalpropagation of electrical power or signals through the conductor of awire via an electrical circuit. In addition to the propagation of guidedwaves 120 and 122, the transmission medium 125 may optionally containone or more wires that propagate electrical power or other communicationsignals in a conventional manner as a part of one or more electricalcircuits.

Referring now to FIG. 2, a block diagram 200 illustrating an example,non-limiting embodiment of a transmission device is shown. Thetransmission device 101 or 102 includes a communications interface (I/F)205, a transceiver 210 and a coupler 220.

In an example of operation, the communications interface 205 receives acommunication signal 110 or 112 that includes data. In variousembodiments, the communications interface 205 can include a wirelessinterface for receiving a wireless communication signal in accordancewith a wireless standard protocol such as LTE or other cellular voiceand data protocol, WiFi or an 802.11 protocol, WIMAX protocol, UltraWideband protocol, Bluetooth protocol, Zigbee protocol, a directbroadcast satellite (DBS) or other satellite communication protocol orother wireless protocol. In addition or in the alternative, thecommunications interface 205 includes a wired interface that operates inaccordance with an Ethernet protocol, universal serial bus (USB)protocol, a data over cable service interface specification (DOCSIS)protocol, a digital subscriber line (DSL) protocol, a Firewire (IEEE1394) protocol, or other wired protocol. In additional tostandards-based protocols, the communications interface 205 can operatein conjunction with other wired or wireless protocol. In addition, thecommunications interface 205 can optionally operate in conjunction witha protocol stack that includes multiple protocol layers including a MACprotocol, transport protocol, application protocol, etc.

In an example of operation, the transceiver 210 generates anelectromagnetic wave based on the communication signal 110 or 112 toconvey the data. The electromagnetic wave has at least one carrierfrequency and at least one corresponding wavelength. The carrierfrequency can be within a millimeter-wave frequency band of 30 GHz-300GHz, such as 60 GHz or a carrier frequency in the range of 30-40 GHz ora lower frequency band of 300 MHz-30 GHz in the microwave frequencyrange such as 26-30 GHz, 11 GHz, 6 GHz or 3 GHz, but it will beappreciated that other carrier frequencies are possible in otherembodiments. In one mode of operation, the transceiver 210 merelyupconverts the communications signal or signals 110 or 112 fortransmission of the electromagnetic signal in the microwave ormillimeter-wave band as a guided electromagnetic wave that is guided byor bound to the transmission medium 125. In another mode of operation,the communications interface 205 either converts the communicationsignal 110 or 112 to a baseband or near baseband signal or extracts thedata from the communication signal 110 or 112 and the transceiver 210modulates a high-frequency carrier with the data, the baseband or nearbaseband signal for transmission. It should be appreciated that thetransceiver 210 can modulate the data received via the communicationsignal 110 or 112 to preserve one or more data communication protocolsof the communication signal 110 or 112 either by encapsulation in thepayload of a different protocol or by simple frequency shifting. In thealternative, the transceiver 210 can otherwise translate the datareceived via the communication signal 110 or 112 to a protocol that isdifferent from the data communication protocol or protocols of thecommunication signal 110 or 112.

In an example of operation, the coupler 220 couples the electromagneticwave to the transmission medium 125 as a guided electromagnetic wave toconvey the communications signal or signals 110 or 112. While the priordescription has focused on the operation of the transceiver 210 as atransmitter, the transceiver 210 can also operate to receiveelectromagnetic waves that convey other data from the single wiretransmission medium via the coupler 220 and to generate communicationssignals 110 or 112, via communications interface 205 that includes theother data. Consider embodiments where an additional guidedelectromagnetic wave conveys other data that also propagates along thetransmission medium 125. The coupler 220 can also couple this additionalelectromagnetic wave from the transmission medium 125 to the transceiver210 for reception.

The transmission device 101 or 102 includes an optional trainingcontroller 230. In an example embodiment, the training controller 230 isimplemented by a standalone processor or a processor that is shared withone or more other components of the transmission device 101 or 102. Thetraining controller 230 selects the carrier frequencies, modulationschemes and/or guided wave modes for the guided electromagnetic wavesbased on feedback data received by the transceiver 210 from at least oneremote transmission device coupled to receive the guided electromagneticwave.

In an example embodiment, a guided electromagnetic wave transmitted by aremote transmission device 101 or 102 conveys data that also propagatesalong the transmission medium 125. The data from the remote transmissiondevice 101 or 102 can be generated to include the feedback data. Inoperation, the coupler 220 also couples the guided electromagnetic wavefrom the transmission medium 125 and the transceiver receives theelectromagnetic wave and processes the electromagnetic wave to extractthe feedback data.

In an example embodiment, the training controller 230 operates based onthe feedback data to evaluate a plurality of candidate frequencies,modulation schemes and/or transmission modes to select a carrierfrequency, modulation scheme and/or transmission mode to enhanceperformance, such as throughput, signal strength, reduce propagationloss, etc.

Consider the following example: a transmission device 101 beginsoperation under control of the training controller 230 by sending aplurality of guided waves as test signals such as pilot waves or othertest signals at a corresponding plurality of candidate frequenciesand/or candidate modes directed to a remote transmission device 102coupled to the transmission medium 125. The guided waves can include, inaddition or in the alternative, test data. The test data can indicatethe particular candidate frequency and/or guide-wave mode of the signal.In an embodiment, the training controller 230 at the remote transmissiondevice 102 receives the test signals and/or test data from any of theguided waves that were properly received and determines the bestcandidate frequency and/or guided wave mode, a set of acceptablecandidate frequencies and/or guided wave modes, or a rank ordering ofcandidate frequencies and/or guided wave modes. This selection ofcandidate frequenc(ies) or/and guided-mode(s) are generated by thetraining controller 230 based on one or more optimizing criteria such asreceived signal strength, bit error rate, packet error rate, signal tonoise ratio, propagation loss, etc. The training controller 230generates feedback data that indicates the selection of candidatefrequenc(ies) or/and guided wave mode(s) and sends the feedback data tothe transceiver 210 for transmission to the transmission device 101. Thetransmission device 101 and 102 can then communicate data with oneanother based on the selection of candidate frequenc(ies) or/and guidedwave mode(s).

In other embodiments, the guided electromagnetic waves that contain thetest signals and/or test data are reflected back, repeated back orotherwise looped back by the remote transmission device 102 to thetransmission device 101 for reception and analysis by the trainingcontroller 230 of the transmission device 101 that initiated thesewaves. For example, the transmission device 101 can send a signal to theremote transmission device 102 to initiate a test mode where a physicalreflector is switched on the line, a termination impedance is changed tocause reflections, a loop back mode is switched on to coupleelectromagnetic waves back to the source transmission device 102, and/ora repeater mode is enabled to amplify and retransmit the electromagneticwaves back to the source transmission device 102. The trainingcontroller 230 at the source transmission device 102 receives the testsignals and/or test data from any of the guided waves that were properlyreceived and determines selection of candidate frequenc(ies) or/andguided wave mode(s).

While the procedure above has been described in a start-up orinitialization mode of operation, each transmission device 101 or 102can send test signals, evaluate candidate frequencies or guided wavemodes via non-test such as normal transmissions or otherwise evaluatecandidate frequencies or guided wave modes at other times orcontinuously as well. In an example embodiment, the communicationprotocol between the transmission devices 101 and 102 can include anon-request or periodic test mode where either full testing or morelimited testing of a subset of candidate frequencies and guided wavemodes are tested and evaluated. In other modes of operation, there-entry into such a test mode can be triggered by a degradation ofperformance due to a disturbance, weather conditions, etc. In an exampleembodiment, the receiver bandwidth of the transceiver 210 is eithersufficiently wide or swept to receive all candidate frequencies or canbe selectively adjusted by the training controller 230 to a trainingmode where the receiver bandwidth of the transceiver 210 is sufficientlywide or swept to receive all candidate frequencies.

Referring now to FIG. 3, a graphical diagram 300 illustrating anexample, non-limiting embodiment of an electromagnetic fielddistribution is shown. In this embodiment, a transmission medium 125 inair includes an inner conductor 301 and an insulating jacket 302 ofdielectric material, as shown in cross section. The diagram 300 includesdifferent gray-scales that represent differing electromagnetic fieldstrengths generated by the propagation of the guided wave having anasymmetrical and non-fundamental guided wave mode.

In particular, the electromagnetic field distribution corresponds to amodal “sweet spot” that enhances guided electromagnetic wave propagationalong an insulated transmission medium and reduces end-to-endtransmission loss. In this particular mode, electromagnetic waves areguided by the transmission medium 125 to propagate along an outersurface of the transmission medium—in this case, the outer surface ofthe insulating jacket 302. Electromagnetic waves are partially embeddedin the insulator and partially radiating on the outer surface of theinsulator. In this fashion, electromagnetic waves are “lightly” coupledto the insulator so as to enable electromagnetic wave propagation atlong distances with low propagation loss.

As shown, the guided wave has a field structure that lies primarily orsubstantially outside of the transmission medium 125 that serves toguide the electromagnetic waves. The regions inside the conductor 301have little or no field. Likewise regions inside the insulating jacket302 have low field strength. The majority of the electromagnetic fieldstrength is distributed in the lobes 304 at the outer surface of theinsulating jacket 302 and in close proximity thereof. The presence of anasymmetric guided wave mode is shown by the high electromagnetic fieldstrengths at the top and bottom of the outer surface of the insulatingjacket 302 (in the orientation of the diagram)—as opposed to very smallfield strengths on the other sides of the insulating jacket 302.

The example shown corresponds to a 38 GHz electromagnetic wave guided bya wire with a diameter of 1.1 cm and a dielectric insulation ofthickness of 0.36 cm. Because the electromagnetic wave is guided by thetransmission medium 125 and the majority of the field strength isconcentrated in the air outside of the insulating jacket 302 within alimited distance of the outer surface, the guided wave can propagatelongitudinally down the transmission medium 125 with very low loss. Inthe example shown, this “limited distance” corresponds to a distancefrom the outer surface that is less than half the largest crosssectional dimension of the transmission medium 125. In this case, thelargest cross sectional dimension of the wire corresponds to the overalldiameter of 1.82 cm, however, this value can vary with the size andshape of the transmission medium 125. For example, should thetransmission medium 125 be of a rectangular shape with a height of 0.3cm and a width of 0.4 cm, the largest cross sectional dimension would bethe diagonal of 0.5 cm and the corresponding limited distance would be0.25 cm. The dimensions of the area containing the majority of the fieldstrength also vary with the frequency, and in general, increase ascarrier frequencies decrease.

It should also be noted that the components of a guided wavecommunication system, such as couplers and transmission media can havetheir own cut-off frequencies for each guided wave mode. The cut-offfrequency generally sets forth the lowest frequency that a particularguided wave mode is designed to be supported by that particularcomponent. In an example embodiment, the particular asymmetric mode ofpropagation shown is induced on the transmission medium 125 by anelectromagnetic wave having a frequency that falls within a limitedrange (such as Fc to 2Fc) of the lower cut-off frequency Fc for thisparticular asymmetric mode. The lower cut-off frequency Fc is particularto the characteristics of transmission medium 125. For embodiments asshown that include an inner conductor 301 surrounded by an insulatingjacket 302, this cutoff frequency can vary based on the dimensions andproperties of the insulating jacket 302 and potentially the dimensionsand properties of the inner conductor 301 and can be determinedexperimentally to have a desired mode pattern. It should be notedhowever, that similar effects can be found for a hollow dielectric orinsulator without an inner conductor. In this case, the cutoff frequencycan vary based on the dimensions and properties of the hollow dielectricor insulator.

At frequencies lower than the lower cut-off frequency, the asymmetricmode is difficult to induce in the transmission medium 125 and fails topropagate for all but trivial distances. As the frequency increasesabove the limited range of frequencies about the cut-off frequency, theasymmetric mode shifts more and more inward of the insulating jacket302. At frequencies much larger than the cut-off frequency, the fieldstrength is no longer concentrated outside of the insulating jacket, butprimarily inside of the insulating jacket 302. While the transmissionmedium 125 provides strong guidance to the electromagnetic wave andpropagation is still possible, ranges are more limited by increasedlosses due to propagation within the insulating jacket 302—as opposed tothe surrounding air.

Referring now to FIG. 4, a graphical diagram 400 illustrating anexample, non-limiting embodiment of an electromagnetic fielddistribution is shown. In particular, a cross section diagram 400,similar to FIG. 3 is shown with common reference numerals used to referto similar elements. The example shown corresponds to a 60 GHz waveguided by a wire with a diameter of 1.1 cm and a dielectric insulationof thickness of 0.36 cm. Because the frequency of the guided wave isabove the limited range of the cut-off frequency of this particularasymmetric mode, much of the field strength has shifted inward of theinsulating jacket 302. In particular, the field strength is concentratedprimarily inside of the insulating jacket 302. While the transmissionmedium 125 provides strong guidance to the electromagnetic wave andpropagation is still possible, ranges are more limited when comparedwith the embodiment of FIG. 3, by increased losses due to propagationwithin the insulating jacket 302.

Referring now to FIG. 5A, a graphical diagram illustrating an example,non-limiting embodiment of a frequency response is shown. In particular,diagram 500 presents a graph of end-to-end loss (in dB) as a function offrequency, overlaid with electromagnetic field distributions 510, 520and 530 at three points for a 200 cm insulated medium voltage wire. Theboundary between the insulator and the surrounding air is represented byreference numeral 525 in each electromagnetic field distribution.

As discussed in conjunction with FIG. 3, an example of a desiredasymmetric mode of propagation shown is induced on the transmissionmedium 125 by an electromagnetic wave having a frequency that fallswithin a limited range (such as Fc to 2Fc) of the lower cut-offfrequency Fc of the transmission medium for this particular asymmetricmode. In particular, the electromagnetic field distribution 520 at 6 GHzfalls within this modal “sweet spot” that enhances electromagnetic wavepropagation along an insulated transmission medium and reducesend-to-end transmission loss. In this particular mode, guided waves arepartially embedded in the insulator and partially radiating on the outersurface of the insulator. In this fashion, the electromagnetic waves are“lightly” coupled to the insulator so as to enable guidedelectromagnetic wave propagation at long distances with low propagationloss.

At lower frequencies represented by the electromagnetic fielddistribution 510 at 3 GHz, the asymmetric mode radiates more heavilygenerating higher propagation losses. At higher frequencies representedby the electromagnetic field distribution 530 at 9 GHz, the asymmetricmode shifts more and more inward of the insulating jacket providing toomuch absorption, again generating higher propagation losses.

Referring now to FIG. 5B, a graphical diagram 550 illustrating example,non-limiting embodiments of a longitudinal cross-section of atransmission medium 125, such as an insulated wire, depicting fields ofguided electromagnetic waves at various operating frequencies is shown.As shown in diagram 556, when the guided electromagnetic waves are atapproximately the cutoff frequency (0 corresponding to the modal “sweetspot”, the guided electromagnetic waves are loosely coupled to theinsulated wire so that absorption is reduced, and the fields of theguided electromagnetic waves are bound sufficiently to reduce the amountradiated into the environment (e.g., air). Because absorption andradiation of the fields of the guided electromagnetic waves is low,propagation losses are consequently low, enabling the guidedelectromagnetic waves to propagate for longer distances.

As shown in diagram 554, propagation losses increase when an operatingfrequency of the guide electromagnetic waves increases above abouttwo-times the cutoff frequency (f_(c))—or as referred to, above therange of the “sweet spot”. More of the field strength of theelectromagnetic wave is driven inside the insulating layer, increasingpropagation losses. At frequencies much higher than the cutoff frequency(k) the guided electromagnetic waves are strongly bound to the insulatedwire as a result of the fields emitted by the guided electromagneticwaves being concentrated in the insulation layer of the wire, as shownin diagram 552. This in turn raises propagation losses further due toabsorption of the guided electromagnetic waves by the insulation layer.Similarly, propagation losses increase when the operating frequency ofthe guided electromagnetic waves is substantially below the cutofffrequency (f_(c)), as shown in diagram 558. At frequencies much lowerthan the cutoff frequency (f_(c)) the guided electromagnetic waves areweakly (or nominally) bound to the insulated wire and thereby tend toradiate into the environment (e.g., air), which in turn, raisespropagation losses due to radiation of the guided electromagnetic waves.

Referring now to FIG. 6, a graphical diagram 600 illustrating anexample, non-limiting embodiment of an electromagnetic fielddistribution is shown. In this embodiment, a transmission medium 602 isa bare wire, as shown in cross section. The diagram 300 includesdifferent gray-scales that represent differing electromagnetic fieldstrengths generated by the propagation of a guided wave having asymmetrical and fundamental guided wave mode at a single carrierfrequency.

In this particular mode, electromagnetic waves are guided by thetransmission medium 602 to propagate along an outer surface of thetransmission medium—in this case, the outer surface of the bare wire.Electromagnetic waves are “lightly” coupled to the wire so as to enableelectromagnetic wave propagation at long distances with low propagationloss. As shown, the guided wave has a field structure that liessubstantially outside of the transmission medium 602 that serves toguide the electromagnetic waves. The regions inside the conductor 602have little or no field.

Referring now to FIG. 7, a block diagram 700 illustrating an example,non-limiting embodiment of an arc coupler is shown. In particular acoupling device is presented for use in a transmission device, such astransmission device 101 or 102 presented in conjunction with FIG. 1. Thecoupling device includes an arc coupler 704 coupled to a transmittercircuit 712 and termination or damper 714. The arc coupler 704 can bemade of a dielectric material, or other low-loss insulator (e.g.,Teflon, polyethylene, etc.), or made of a conducting (e.g., metallic,non-metallic, etc.) material, or any combination of the foregoingmaterials. As shown, the arc coupler 704 operates as a waveguide and hasa wave 706 propagating as a guided wave about a waveguide surface of thearc coupler 704. In the embodiment shown, at least a portion of the arccoupler 704 can be placed near a wire 702 or other transmission medium,(such as transmission medium 125), in order to facilitate couplingbetween the arc coupler 704 and the wire 702 or other transmissionmedium, as described herein to launch the guided wave 708 on the wire.The arc coupler 704 can be placed such that a portion of the curved arccoupler 704 is tangential to, and parallel or substantially parallel tothe wire 702. The portion of the arc coupler 704 that is parallel to thewire can be an apex of the curve, or any point where a tangent of thecurve is parallel to the wire 702. When the arc coupler 704 ispositioned or placed thusly, the wave 706 travelling along the arccoupler 704 couples, at least in part, to the wire 702, and propagatesas guided wave 708 around or about the wire surface of the wire 702 andlongitudinally along the wire 702. The guided wave 708 can becharacterized as a surface wave or other electromagnetic wave that isguided by or bound to the wire 702 or other transmission medium.

A portion of the wave 706 that does not couple to the wire 702propagates as a wave 710 along the arc coupler 704. It will beappreciated that the arc coupler 704 can be configured and arranged in avariety of positions in relation to the wire 702 to achieve a desiredlevel of coupling or non-coupling of the wave 706 to the wire 702. Forexample, the curvature and/or length of the arc coupler 704 that isparallel or substantially parallel, as well as its separation distance(which can include zero separation distance in an embodiment), to thewire 702 can be varied without departing from example embodiments.Likewise, the arrangement of arc coupler 704 in relation to the wire 702may be varied based upon considerations of the respective intrinsiccharacteristics (e.g., thickness, composition, electromagneticproperties, etc.) of the wire 702 and the arc coupler 704, as well asthe characteristics (e.g., frequency, energy level, etc.) of the waves706 and 708.

The guided wave 708 stays parallel or substantially parallel to the wire702, even as the wire 702 bends and flexes. Bends in the wire 702 canincrease transmission losses, which are also dependent on wirediameters, frequency, and materials. If the dimensions of the arccoupler 704 are chosen for efficient power transfer, most of the powerin the wave 706 is transferred to the wire 702, with little powerremaining in wave 710. It will be appreciated that the guided wave 708can still be multi-modal in nature (discussed herein), including havingmodes that are non-fundamental or asymmetric, while traveling along apath that is parallel or substantially parallel to the wire 702, with orwithout a fundamental transmission mode. In an embodiment,non-fundamental or asymmetric modes can be utilized to minimizetransmission losses and/or obtain increased propagation distances.

It is noted that the term parallel is generally a geometric constructwhich often is not exactly achievable in real systems. Accordingly, theterm parallel as utilized in the subject disclosure represents anapproximation rather than an exact configuration when used to describeembodiments disclosed in the subject disclosure. In an embodiment,substantially parallel can include approximations that are within 30degrees of true parallel in all dimensions.

In an embodiment, the wave 706 can exhibit one or more wave propagationmodes. The arc coupler modes can be dependent on the shape and/or designof the coupler 704. The one or more arc coupler modes of wave 706 cangenerate, influence, or impact one or more wave propagation modes of theguided wave 708 propagating along wire 702. It should be particularlynoted however that the guided wave modes present in the guided wave 706may be the same or different from the guided wave modes of the guidedwave 708. In this fashion, one or more guided wave modes of the guidedwave 706 may not be transferred to the guided wave 708, and further oneor more guided wave modes of guided wave 708 may not have been presentin guided wave 706. It should also be noted that the cut-off frequencyof the arc coupler 704 for a particular guided wave mode may bedifferent than the cutoff frequency of the wire 702 or othertransmission medium for that same mode. For example, while the wire 702or other transmission medium may be operated slightly above its cutofffrequency for a particular guided wave mode, the arc coupler 704 may beoperated well above its cut-off frequency for that same mode for lowloss, slightly below its cut-off frequency for that same mode to, forexample, induce greater coupling and power transfer, or some other pointin relation to the arc coupler's cutoff frequency for that mode.

In an embodiment, the wave propagation modes on the wire 702 can besimilar to the arc coupler modes since both waves 706 and 708 propagateabout the outside of the arc coupler 704 and wire 702 respectively. Insome embodiments, as the wave 706 couples to the wire 702, the modes canchange form, or new modes can be created or generated, due to thecoupling between the arc coupler 704 and the wire 702. For example,differences in size, material, and/or impedances of the arc coupler 704and wire 702 may create additional modes not present in the arc couplermodes and/or suppress some of the arc coupler modes. The wavepropagation modes can comprise the fundamental transverseelectromagnetic mode (Quasi-TEM₀₀), where only small electric and/ormagnetic fields extend in the direction of propagation, and the electricand magnetic fields extend radially outwards while the guided wavepropagates along the wire. This guided wave mode can be donut shaped,where few of the electromagnetic fields exist within the arc coupler 704or wire 702.

Waves 706 and 708 can comprise a fundamental TEM mode where the fieldsextend radially outwards, and also comprise other, non-fundamental(e.g., asymmetric, higher-level, etc.) modes. While particular wavepropagation modes are discussed above, other wave propagation modes arelikewise possible such as transverse electric (TE) and transversemagnetic (TM) modes, based on the frequencies employed, the design ofthe arc coupler 704, the dimensions and composition of the wire 702, aswell as its surface characteristics, its insulation if present, theelectromagnetic properties of the surrounding environment, etc. Itshould be noted that, depending on the frequency, the electrical andphysical characteristics of the wire 702 and the particular wavepropagation modes that are generated, guided wave 708 can travel alongthe conductive surface of an oxidized uninsulated wire, an unoxidizeduninsulated wire, an insulated wire and/or along the insulating surfaceof an insulated wire.

In an embodiment, a diameter of the arc coupler 704 is smaller than thediameter of the wire 702. For the millimeter-band wavelength being used,the arc coupler 704 supports a single waveguide mode that makes up wave706. This single waveguide mode can change as it couples to the wire 702as guided wave 708. If the arc coupler 704 were larger, more than onewaveguide mode can be supported, but these additional waveguide modesmay not couple to the wire 702 as efficiently, and higher couplinglosses can result. However, in some alternative embodiments, thediameter of the arc coupler 704 can be equal to or larger than thediameter of the wire 702, for example, where higher coupling losses aredesirable or when used in conjunction with other techniques to otherwisereduce coupling losses (e.g., impedance matching with tapering, etc.).

In an embodiment, the wavelength of the waves 706 and 708 are comparablein size, or smaller than a circumference of the arc coupler 704 and thewire 702. In an example, if the wire 702 has a diameter of 0.5 cm, and acorresponding circumference of around 1.5 cm, the wavelength of thetransmission is around 1.5 cm or less, corresponding to a frequency of70 GHz or greater. In another embodiment, a suitable frequency of thetransmission and the carrier-wave signal is in the range of 30-100 GHz,perhaps around 30-60 GHz, and around 38 GHz in one example. In anembodiment, when the circumference of the arc coupler 704 and wire 702is comparable in size to, or greater, than a wavelength of thetransmission, the waves 706 and 708 can exhibit multiple wavepropagation modes including fundamental and/or non-fundamental(symmetric and/or asymmetric) modes that propagate over sufficientdistances to support various communication systems described herein. Thewaves 706 and 708 can therefore comprise more than one type of electricand magnetic field configuration. In an embodiment, as the guided wave708 propagates down the wire 702, the electrical and magnetic fieldconfigurations will remain the same from end to end of the wire 702. Inother embodiments, as the guided wave 708 encounters interference(distortion or obstructions) or loses energy due to transmission lossesor scattering, the electric and magnetic field configurations can changeas the guided wave 708 propagates down wire 702.

In an embodiment, the arc coupler 704 can be composed of nylon, Teflon,polyethylene, a polyamide, or other plastics. In other embodiments,other dielectric materials are possible. The wire surface of wire 702can be metallic with either a bare metallic surface, or can be insulatedusing plastic, dielectric, insulator or other coating, jacket orsheathing. In an embodiment, a dielectric or otherwisenon-conducting/insulated waveguide can be paired with either abare/metallic wire or insulated wire. In other embodiments, a metallicand/or conductive waveguide can be paired with a bare/metallic wire orinsulated wire. In an embodiment, an oxidation layer on the baremetallic surface of the wire 702 (e.g., resulting from exposure of thebare metallic surface to oxygen/air) can also provide insulating ordielectric properties similar to those provided by some insulators orsheathings.

It is noted that the graphical representations of waves 706, 708 and 710are presented merely to illustrate the principles that wave 706 inducesor otherwise launches a guided wave 708 on a wire 702 that operates, forexample, as a single wire transmission line. Wave 710 represents theportion of wave 706 that remains on the arc coupler 704 after thegeneration of guided wave 708. The actual electric and magnetic fieldsgenerated as a result of such wave propagation may vary depending on thefrequencies employed, the particular wave propagation mode or modes, thedesign of the arc coupler 704, the dimensions and composition of thewire 702, as well as its surface characteristics, its optionalinsulation, the electromagnetic properties of the surroundingenvironment, etc.

It is noted that arc coupler 704 can include a termination circuit ordamper 714 at the end of the arc coupler 704 that can absorb leftoverradiation or energy from wave 710. The termination circuit or damper 714can prevent and/or minimize the leftover radiation or energy from wave710 reflecting back toward transmitter circuit 712. In an embodiment,the termination circuit or damper 714 can include termination resistors,and/or other components that perform impedance matching to attenuatereflection. In some embodiments, if the coupling efficiencies are highenough, and/or wave 710 is sufficiently small, it may not be necessaryto use a termination circuit or damper 714. For the sake of simplicity,these transmitter 712 and termination circuits or dampers 714 may not bedepicted in the other figures, but in those embodiments, transmitter andtermination circuits or dampers may possibly be used.

Further, while a single arc coupler 704 is presented that generates asingle guided wave 708, multiple arc couplers 704 placed at differentpoints along the wire 702 and/or at different azimuthal orientationsabout the wire can be employed to generate and receive multiple guidedwaves 708 at the same or different frequencies, at the same or differentphases, at the same or different wave propagation modes.

FIG. 8, a block diagram 800 illustrating an example, non-limitingembodiment of an arc coupler is shown. In the embodiment shown, at leasta portion of the coupler 704 can be placed near a wire 702 or othertransmission medium, (such as transmission medium 125), in order tofacilitate coupling between the arc coupler 704 and the wire 702 orother transmission medium, to extract a portion of the guided wave 806as a guided wave 808 as described herein. The arc coupler 704 can beplaced such that a portion of the curved arc coupler 704 is tangentialto, and parallel or substantially parallel to the wire 702. The portionof the arc coupler 704 that is parallel to the wire can be an apex ofthe curve, or any point where a tangent of the curve is parallel to thewire 702. When the arc coupler 704 is positioned or placed thusly, thewave 806 travelling along the wire 702 couples, at least in part, to thearc coupler 704, and propagates as guided wave 808 along the arc coupler704 to a receiving device (not expressly shown). A portion of the wave806 that does not couple to the arc coupler propagates as wave 810 alongthe wire 702 or other transmission medium.

In an embodiment, the wave 806 can exhibit one or more wave propagationmodes. The arc coupler modes can be dependent on the shape and/or designof the coupler 704. The one or more modes of guided wave 806 cangenerate, influence, or impact one or more guide-wave modes of theguided wave 808 propagating along the arc coupler 704. It should beparticularly noted however that the guided wave modes present in theguided wave 806 may be the same or different from the guided wave modesof the guided wave 808. In this fashion, one or more guided wave modesof the guided wave 806 may not be transferred to the guided wave 808,and further one or more guided wave modes of guided wave 808 may nothave been present in guided wave 806.

Referring now to FIG. 9A, a block diagram 900 illustrating an example,non-limiting embodiment of a stub coupler is shown. In particular acoupling device that includes stub coupler 904 is presented for use in atransmission device, such as transmission device 101 or 102 presented inconjunction with FIG. 1. The stub coupler 904 can be made of adielectric material, or other low-loss insulator (e.g., Teflon,polyethylene and etc.), or made of a conducting (e.g., metallic,non-metallic, etc.) material, or any combination of the foregoingmaterials. As shown, the stub coupler 904 operates as a waveguide andhas a wave 906 propagating as a guided wave about a waveguide surface ofthe stub coupler 904. In the embodiment shown, at least a portion of thestub coupler 904 can be placed near a wire 702 or other transmissionmedium, (such as transmission medium 125), in order to facilitatecoupling between the stub coupler 904 and the wire 702 or othertransmission medium, as described herein to launch the guided wave 908on the wire.

In an embodiment, the stub coupler 904 is curved, and an end of the stubcoupler 904 can be tied, fastened, or otherwise mechanically coupled toa wire 702. When the end of the stub coupler 904 is fastened to the wire702, the end of the stub coupler 904 is parallel or substantiallyparallel to the wire 702. Alternatively, another portion of thedielectric waveguide beyond an end can be fastened or coupled to wire702 such that the fastened or coupled portion is parallel orsubstantially parallel to the wire 702. The fastener 910 can be a nyloncable tie or other type of non-conducting/dielectric material that iseither separate from the stub coupler 904 or constructed as anintegrated component of the stub coupler 904. The stub coupler 904 canbe adjacent to the wire 702 without surrounding the wire 702.

Like the arc coupler 704 described in conjunction with FIG. 7, when thestub coupler 904 is placed with the end parallel to the wire 702, theguided wave 906 travelling along the stub coupler 904 couples to thewire 702, and propagates as guided wave 908 about the wire surface ofthe wire 702. In an example embodiment, the guided wave 908 can becharacterized as a surface wave or other electromagnetic wave.

It is noted that the graphical representations of waves 906 and 908 arepresented merely to illustrate the principles that wave 906 induces orotherwise launches a guided wave 908 on a wire 702 that operates, forexample, as a single wire transmission line. The actual electric andmagnetic fields generated as a result of such wave propagation may varydepending on one or more of the shape and/or design of the coupler, therelative position of the dielectric waveguide to the wire, thefrequencies employed, the design of the stub coupler 904, the dimensionsand composition of the wire 702, as well as its surface characteristics,its optional insulation, the electromagnetic properties of thesurrounding environment, etc.

In an embodiment, an end of stub coupler 904 can taper towards the wire702 in order to increase coupling efficiencies. Indeed, the tapering ofthe end of the stub coupler 904 can provide impedance matching to thewire 702 and reduce reflections, according to an example embodiment ofthe subject disclosure. For example, an end of the stub coupler 904 canbe gradually tapered in order to obtain a desired level of couplingbetween waves 906 and 908 as illustrated in FIG. 9A.

In an embodiment, the fastener 910 can be placed such that there is ashort length of the stub coupler 904 between the fastener 910 and an endof the stub coupler 904. Maximum coupling efficiencies are realized inthis embodiment when the length of the end of the stub coupler 904 thatis beyond the fastener 910 is at least several wavelengths long forwhatever frequency is being transmitted.

Turning now to FIG. 9B, a diagram 950 illustrating an example,non-limiting embodiment of an electromagnetic distribution in accordancewith various aspects described herein is shown. In particular, anelectromagnetic distribution is presented in two dimensions for atransmission device that includes coupler 952, shown in an example stubcoupler constructed of a dielectric material. The coupler 952 couples anelectromagnetic wave for propagation as a guided wave along an outersurface of a wire 702 or other transmission medium.

The coupler 952 guides the electromagnetic wave to a junction at x₀ viaa symmetrical guided wave mode. While some of the energy of theelectromagnetic wave that propagates along the coupler 952 is outside ofthe coupler 952, the majority of the energy of this electromagnetic waveis contained within the coupler 952. The junction at x₀ couples theelectromagnetic wave to the wire 702 or other transmission medium at anazimuthal angle corresponding to the bottom of the transmission medium.This coupling induces an electromagnetic wave that is guided topropagate along the outer surface of the wire 702 or other transmissionmedium via at least one guided wave mode in direction 956. The majorityof the energy of the guided electromagnetic wave is outside or, but inclose proximity to the outer surface of the wire 702 or othertransmission medium. In the example shown, the junction at x₀ forms anelectromagnetic wave that propagates via both a symmetrical mode and atleast one asymmetrical surface mode, such as the first order modepresented in conjunction with FIG. 3, that skims the surface of the wire702 or other transmission medium.

It is noted that the graphical representations of guided waves arepresented merely to illustrate an example of guided wave coupling andpropagation. The actual electric and magnetic fields generated as aresult of such wave propagation may vary depending on the frequenciesemployed, the design and/or configuration of the coupler 952, thedimensions and composition of the wire 702 or other transmission medium,as well as its surface characteristics, its insulation if present, theelectromagnetic properties of the surrounding environment, etc.

Turning now to FIG. 10A, illustrated is a block diagram 1000 of anexample, non-limiting embodiment of a coupler and transceiver system inaccordance with various aspects described herein. The system is anexample of transmission device 101 or 102. In particular, thecommunication interface 1008 is an example of communications interface205, the stub coupler 1002 is an example of coupler 220, and thetransmitter/receiver device 1006, diplexer 1016, power amplifier 1014,low noise amplifier 1018, frequency mixers 1010 and 1020 and localoscillator 1012 collectively form an example of transceiver 210.

In operation, the transmitter/receiver device 1006 launches and receiveswaves (e.g., guided wave 1004 onto stub coupler 1002). The guided waves1004 can be used to transport signals received from and sent to a hostdevice, base station, mobile devices, a building or other device by wayof a communications interface 1008. The communications interface 1008can be an integral part of system 1000. Alternatively, thecommunications interface 1008 can be tethered to system 1000. Thecommunications interface 1008 can comprise a wireless interface forinterfacing to the host device, base station, mobile devices, a buildingor other device utilizing any of various wireless signaling protocols(e.g., LTE, WiFi, WiMAX, IEEE 802.xx, etc.) including an infraredprotocol such as an infrared data association (IrDA) protocol or otherline of sight optical protocol. The communications interface 1008 canalso comprise a wired interface such as a fiber optic line, coaxialcable, twisted pair, category 5 (CAT-5) cable or other suitable wired oroptical mediums for communicating with the host device, base station,mobile devices, a building or other device via a protocol such as anEthernet protocol, universal serial bus (USB) protocol, a data overcable service interface specification (DOCSIS) protocol, a digitalsubscriber line (DSL) protocol, a Firewire (IEEE 1394) protocol, orother wired or optical protocol. For embodiments where system 1000functions as a repeater, the communications interface 1008 may not benecessary.

The output signals (e.g., Tx) of the communications interface 1008 canbe combined with a carrier wave (e g, millimeter-wave carrier wave)generated by a local oscillator 1012 at frequency mixer 1010. Frequencymixer 1010 can use heterodyning techniques or other frequency shiftingtechniques to frequency shift the output signals from communicationsinterface 1008. For example, signals sent to and from the communicationsinterface 1008 can be modulated signals such as orthogonal frequencydivision multiplexed (OFDM) signals formatted in accordance with aLong-Term Evolution (LTE) wireless protocol or other wireless 3G, 4G, 5Gor higher voice and data protocol, a Zigbee, WIMAX, UltraWideband orIEEE 802.11 wireless protocol; a wired protocol such as an Ethernetprotocol, universal serial bus (USB) protocol, a data over cable serviceinterface specification (DOCSIS) protocol, a digital subscriber line(DSL) protocol, a Firewire (IEEE 1394) protocol or other wired orwireless protocol. In an example embodiment, this frequency conversioncan be done in the analog domain, and as a result, the frequencyshifting can be done without regard to the type of communicationsprotocol used by a base station, mobile devices, or in-building devices.As new communications technologies are developed, the communicationsinterface 1008 can be upgraded (e.g., updated with software, firmware,and/or hardware) or replaced and the frequency shifting and transmissionapparatus can remain, simplifying upgrades. The carrier wave can then besent to a power amplifier (“PA”) 1014 and can be transmitted via thetransmitter receiver device 1006 via the diplexer 1016.

Signals received from the transmitter/receiver device 1006 that aredirected towards the communications interface 1008 can be separated fromother signals via diplexer 1016. The received signal can then be sent tolow noise amplifier (“LNA”) 1018 for amplification. A frequency mixer1020, with help from local oscillator 1012 can downshift the receivedsignal (which is in the millimeter-wave band or around 38 GHz in someembodiments) to the native frequency. The communications interface 1008can then receive the transmission at an input port (Rx).

In an embodiment, transmitter/receiver device 1006 can include acylindrical or non-cylindrical metal (which, for example, can be hollowin an embodiment, but not necessarily drawn to scale) or otherconducting or non-conducting waveguide and an end of the stub coupler1002 can be placed in or in proximity to the waveguide or thetransmitter/receiver device 1006 such that when the transmitter/receiverdevice 1006 generates a transmission, the guided wave couples to stubcoupler 1002 and propagates as a guided wave 1004 about the waveguidesurface of the stub coupler 1002. In some embodiments, the guided wave1004 can propagate in part on the outer surface of the stub coupler 1002and in part inside the stub coupler 1002. In other embodiments, theguided wave 1004 can propagate substantially or completely on the outersurface of the stub coupler 1002. In yet other embodiments, the guidedwave 1004 can propagate substantially or completely inside the stubcoupler 1002. In this latter embodiment, the guided wave 1004 canradiate at an end of the stub coupler 1002 (such as the tapered endshown in FIG. 4) for coupling to a transmission medium such as a wire702 of FIG. 7. Similarly, if guided wave 1004 is incoming (coupled tothe stub coupler 1002 from a wire 702), guided wave 1004 then enters thetransmitter/receiver device 1006 and couples to the cylindricalwaveguide or conducting waveguide. While transmitter/receiver device1006 is shown to include a separate waveguide—an antenna, cavityresonator, klystron, magnetron, travelling wave tube, or other radiatingelement can be employed to induce a guided wave on the coupler 1002,with or without the separate waveguide.

In an embodiment, stub coupler 1002 can be wholly constructed of adielectric material (or another suitable insulating material), withoutany metallic or otherwise conducting materials therein. Stub coupler1002 can be composed of nylon, Teflon, polyethylene, a polyamide, otherplastics, or other materials that are non-conducting and suitable forfacilitating transmission of electromagnetic waves at least in part onan outer surface of such materials. In another embodiment, stub coupler1002 can include a core that is conducting/metallic, and have anexterior dielectric surface. Similarly, a transmission medium thatcouples to the stub coupler 1002 for propagating electromagnetic wavesinduced by the stub coupler 1002 or for supplying electromagnetic wavesto the stub coupler 1002 can, in addition to being a bare or insulatedwire, be wholly constructed of a dielectric material (or anothersuitable insulating material), without any metallic or otherwiseconducting materials therein.

It is noted that although FIG. 10A shows that the opening of transmitterreceiver device 1006 is much wider than the stub coupler 1002, this isnot to scale, and that in other embodiments the width of the stubcoupler 1002 is comparable or slightly smaller than the opening of thehollow waveguide. It is also not shown, but in an embodiment, an end ofthe coupler 1002 that is inserted into the transmitter/receiver device1006 tapers down in order to reduce reflection and increase couplingefficiencies.

Before coupling to the stub coupler 1002, the one or more waveguidemodes of the guided wave generated by the transmitter/receiver device1006 can couple to the stub coupler 1002 to induce one or more wavepropagation modes of the guided wave 1004. The wave propagation modes ofthe guided wave 1004 can be different than the hollow metal waveguidemodes due to the different characteristics of the hollow metal waveguideand the dielectric waveguide. For instance, wave propagation modes ofthe guided wave 1004 can comprise the fundamental transverseelectromagnetic mode (Quasi-TEM₀₀), where only small electrical and/ormagnetic fields extend in the direction of propagation, and the electricand magnetic fields extend radially outwards from the stub coupler 1002while the guided waves propagate along the stub coupler 1002. Thefundamental transverse electromagnetic mode wave propagation mode may ormay not exist inside a waveguide that is hollow. Therefore, the hollowmetal waveguide modes that are used by transmitter/receiver device 1006are waveguide modes that can couple effectively and efficiently to wavepropagation modes of stub coupler 1002.

It will be appreciated that other constructs or combinations of thetransmitter/receiver device 1006 and stub coupler 1002 are possible. Forexample, a stub coupler 1002′ can be placed tangentially or in parallel(with or without a gap) with respect to an outer surface of the hollowmetal waveguide of the transmitter/receiver device 1006′ (correspondingcircuitry not shown) as depicted by reference 1000′ of FIG. 10B. Inanother embodiment, not shown by reference 1000′, the stub coupler 1002′can be placed inside the hollow metal waveguide of thetransmitter/receiver device 1006′ without an axis of the stub coupler1002′ being coaxially aligned with an axis of the hollow metal waveguideof the transmitter/receiver device 1006′. In either of theseembodiments, the guided wave generated by the transmitter/receiverdevice 1006′ can couple to a surface of the stub coupler 1002′ to induceone or more wave propagation modes of the guided wave 1004′ on the stubcoupler 1002′ including a fundamental mode (e.g., a symmetric mode)and/or a non-fundamental mode (e.g., asymmetric mode).

In one embodiment, the guided wave 1004′ can propagate in part on theouter surface of the stub coupler 1002′ and in part inside the stubcoupler 1002′. In another embodiment, the guided wave 1004′ canpropagate substantially or completely on the outer surface of the stubcoupler 1002′. In yet other embodiments, the guided wave 1004′ canpropagate substantially or completely inside the stub coupler 1002′. Inthis latter embodiment, the guided wave 1004′ can radiate at an end ofthe stub coupler 1002′ (such as the tapered end shown in FIG. 9) forcoupling to a transmission medium such as a wire 702 of FIG. 9.

It will be further appreciated that other constructs thetransmitter/receiver device 1006 are possible. For example, a hollowmetal waveguide of a transmitter/receiver device 1006″ (correspondingcircuitry not shown), depicted in FIG. 10B as reference 1000″, can beplaced tangentially or in parallel (with or without a gap) with respectto an outer surface of a transmission medium such as the wire 702 ofFIG. 4 without the use of the stub coupler 1002. In this embodiment, theguided wave generated by the transmitter/receiver device 1006″ cancouple to a surface of the wire 702 to induce one or more wavepropagation modes of a guided wave 908 on the wire 702 including afundamental mode (e.g., a symmetric mode) and/or a non-fundamental mode(e.g., asymmetric mode). In another embodiment, the wire 702 can bepositioned inside a hollow metal waveguide of a transmitter/receiverdevice 1006′ (corresponding circuitry not shown) so that an axis of thewire 702 is coaxially (or not coaxially) aligned with an axis of thehollow metal waveguide without the use of the stub coupler 1002—see FIG.10B reference 1000′″. In this embodiment, the guided wave generated bythe transmitter/receiver device 1006′″ can couple to a surface of thewire 702 to induce one or more wave propagation modes of a guided wave908 on the wire including a fundamental mode (e.g., a symmetric mode)and/or a non-fundamental mode (e.g., asymmetric mode).

In the embodiments of 1000″ and 1000′″, for a wire 702 having aninsulated outer surface, the guided wave 908 can propagate in part onthe outer surface of the insulator and in part inside the insulator. Inembodiments, the guided wave 908 can propagate substantially orcompletely on the outer surface of the insulator, or substantially orcompletely inside the insulator. In the embodiments of 1000″ and 1000′″,for a wire 702 that is a bare conductor, the guided wave 908 canpropagate in part on the outer surface of the conductor and in partinside the conductor. In another embodiment, the guided wave 908 canpropagate substantially or completely on the outer surface of theconductor.

Referring now to FIG. 11, a block diagram 1100 illustrating an example,non-limiting embodiment of a dual stub coupler is shown. In particular,a dual coupler design is presented for use in a transmission device,such as transmission device 101 or 102 presented in conjunction withFIG. 1. In an embodiment, two or more couplers (such as the stubcouplers 1104 and 1106) can be positioned around a wire 1102 in order toreceive guided wave 1108. In an embodiment, one coupler is enough toreceive the guided wave 1108. In that case, guided wave 1108 couples tocoupler 1104 and propagates as guided wave 1110. If the field structureof the guided wave 1108 oscillates or undulates around the wire 1102 dueto the particular guided wave mode(s) or various outside factors, thencoupler 1106 can be placed such that guided wave 1108 couples to coupler1106. In some embodiments, four or more couplers can be placed around aportion of the wire 1102, e.g., at 90 degrees or another spacing withrespect to each other, in order to receive guided waves that mayoscillate or rotate around the wire 1102, that have been induced atdifferent azimuthal orientations or that have non-fundamental or higherorder modes that, for example, have lobes and/or nulls or otherasymmetries that are orientation dependent. However, it will beappreciated that there may be less than or more than four couplersplaced around a portion of the wire 1102 without departing from exampleembodiments.

It should be noted that while couplers 1106 and 1104 are illustrated asstub couplers, any other of the coupler designs described hereinincluding arc couplers, antenna or horn couplers, magnetic couplers,etc., could likewise be used. It will also be appreciated that whilesome example embodiments have presented a plurality of couplers aroundat least a portion of a wire 1102, this plurality of couplers can alsobe considered as part of a single coupler system having multiple couplersubcomponents. For example, two or more couplers can be manufactured assingle system that can be installed around a wire in a singleinstallation such that the couplers are either pre-positioned oradjustable relative to each other (either manually or automatically witha controllable mechanism such as a motor or other actuator) inaccordance with the single system.

Receivers coupled to couplers 1106 and 1104 can use diversity combiningto combine signals received from both couplers 1106 and 1104 in order tomaximize the signal quality. In other embodiments, if one or the otherof the couplers 1104 and 1106 receive a transmission that is above apredetermined threshold, receivers can use selection diversity whendeciding which signal to use. Further, while reception by a plurality ofcouplers 1106 and 1104 is illustrated, transmission by couplers 1106 and1104 in the same configuration can likewise take place. In particular, awide range of multi-input multi-output (MIMO) transmission and receptiontechniques can be employed for transmissions where a transmissiondevice, such as transmission device 101 or 102 presented in conjunctionwith FIG. 1 includes multiple transceivers and multiple couplers.

It is noted that the graphical representations of waves 1108 and 1110are presented merely to illustrate the principles that guided wave 1108induces or otherwise launches a wave 1110 on a coupler 1104. The actualelectric and magnetic fields generated as a result of such wavepropagation may vary depending on the frequencies employed, the designof the coupler 1104, the dimensions and composition of the wire 1102, aswell as its surface characteristics, its insulation if any, theelectromagnetic properties of the surrounding environment, etc.

Referring now to FIG. 12, a block diagram 1200 illustrating an example,non-limiting embodiment of a repeater system is shown. In particular, arepeater device 1210 is presented for use in a transmission device, suchas transmission device 101 or 102 presented in conjunction with FIG. 1.In this system, two couplers 1204 and 1214 can be placed near a wire1202 or other transmission medium such that guided waves 1205propagating along the wire 1202 are extracted by coupler 1204 as wave1206 (e.g. as a guided wave), and then are boosted or repeated byrepeater device 1210 and launched as a wave 1216 (e.g. as a guided wave)onto coupler 1214. The wave 1216 can then be launched on the wire 1202and continue to propagate along the wire 1202 as a guided wave 1217. Inan embodiment, the repeater device 1210 can receive at least a portionof the power utilized for boosting or repeating through magneticcoupling with the wire 1202, for example, when the wire 1202 is a powerline or otherwise contains a power-carrying conductor. It should benoted that while couplers 1204 and 1214 are illustrated as stubcouplers, any other of the coupler designs described herein includingarc couplers, antenna or horn couplers, magnetic couplers, or the like,could likewise be used.

In some embodiments, repeater device 1210 can repeat the transmissionassociated with wave 1206, and in other embodiments, repeater device1210 can include a communications interface 205 that extracts data orother signals from the wave 1206 for supplying such data or signals toanother network and/or one or more other devices as communicationsignals 110 or 112 and/or receiving communication signals 110 or 112from another network and/or one or more other devices and launch guidedwave 1216 having embedded therein the received communication signals 110or 112. In a repeater configuration, receiver waveguide 1208 can receivethe wave 1206 from the coupler 1204 and transmitter waveguide 1212 canlaunch guided wave 1216 onto coupler 1214 as guided wave 1217. Betweenreceiver waveguide 1208 and transmitter waveguide 1212, the signalembedded in guided wave 1206 and/or the guided wave 1216 itself can beamplified to correct for signal loss and other inefficiencies associatedwith guided wave communications or the signal can be received andprocessed to extract the data contained therein and regenerated fortransmission. In an embodiment, the receiver waveguide 1208 can beconfigured to extract data from the signal, process the data to correctfor data errors utilizing for example error correcting codes, andregenerate an updated signal with the corrected data. The transmitterwaveguide 1212 can then transmit guided wave 1216 with the updatedsignal embedded therein. In an embodiment, a signal embedded in guidedwave 1206 can be extracted from the transmission and processed forcommunication with another network and/or one or more other devices viacommunications interface 205 as communication signals 110 or 112.Similarly, communication signals 110 or 112 received by thecommunications interface 205 can be inserted into a transmission ofguided wave 1216 that is generated and launched onto coupler 1214 bytransmitter waveguide 1212.

It is noted that although FIG. 12 shows guided wave transmissions 1206and 1216 entering from the left and exiting to the right respectively,this is merely a simplification and is not intended to be limiting. Inother embodiments, receiver waveguide 1208 and transmitter waveguide1212 can also function as transmitters and receivers respectively,allowing the repeater device 1210 to be bi-directional.

In an embodiment, repeater device 1210 can be placed at locations wherethere are discontinuities or obstacles on the wire 1202 or othertransmission medium. In the case where the wire 1202 is a power line,these obstacles can include transformers, connections, utility poles,and other such power line devices. The repeater device 1210 can help theguided (e.g., surface) waves jump over these obstacles on the line andboost the transmission power at the same time. In other embodiments, acoupler can be used to jump over the obstacle without the use of arepeater device. In that embodiment, both ends of the coupler can betied or fastened to the wire, thus providing a path for the guided waveto travel without being blocked by the obstacle.

Turning now to FIG. 13, illustrated is a block diagram 1300 of anexample, non-limiting embodiment of a bidirectional repeater inaccordance with various aspects described herein. In particular, abidirectional repeater device 1306 is presented for use in atransmission device, such as transmission device 101 or 102 presented inconjunction with FIG. 1. It should be noted that while the couplers areillustrated as stub couplers, any other of the coupler designs describedherein including arc couplers, antenna or horn couplers, magneticcouplers, or the like, could likewise be used. The bidirectionalrepeater 1306 can employ diversity paths in the case of when two or morewires or other transmission media are present. Since guided wavetransmissions have different transmission efficiencies and couplingefficiencies for transmission medium of different types such asinsulated wires, un-insulated wires or other types of transmission mediaand further, if exposed to the elements, can be affected by weather, andother atmospheric conditions, it can be advantageous to selectivelytransmit on different transmission media at certain times. In variousembodiments, the various transmission media can be designated as aprimary, secondary, tertiary, etc. whether or not such designationindicates a preference of one transmission medium over another.

In the embodiment shown, the transmission media include an insulated oruninsulated wire 1302 and an insulated or uninsulated wire 1304(referred to herein as wires 1302 and 1304, respectively). The repeaterdevice 1306 uses a receiver coupler 1308 to receive a guided wavetraveling along wire 1302 and repeats the transmission using transmitterwaveguide 1310 as a guided wave along wire 1304. In other embodiments,repeater device 1306 can switch from the wire 1304 to the wire 1302, orcan repeat the transmissions along the same paths. Repeater device 1306can include sensors, or be in communication with sensors (or a networkmanagement system 1601 depicted in FIG. 16A) that indicate conditionsthat can affect the transmission. Based on the feedback received fromthe sensors, the repeater device 1306 can make the determination aboutwhether to keep the transmission along the same wire, or transfer thetransmission to the other wire.

Turning now to FIG. 14, illustrated is a block diagram 1400 illustratingan example, non-limiting embodiment of a bidirectional repeater system.In particular, a bidirectional repeater system is presented for use in atransmission device, such as transmission device 101 or 102 presented inconjunction with FIG. 1. The bidirectional repeater system includeswaveguide coupling devices 1402 and 1404 that receive and transmittransmissions from other coupling devices located in a distributedantenna system or backhaul system.

In various embodiments, waveguide coupling device 1402 can receive atransmission from another waveguide coupling device, wherein thetransmission has a plurality of subcarriers. Diplexer 1406 can separatethe transmission from other transmissions, and direct the transmissionto low-noise amplifier (“LNA”) 1408. A frequency mixer 1428, with helpfrom a local oscillator 1412, can downshift the transmission (which isin the millimeter-wave band or around 38 GHz in some embodiments) to alower frequency, such as a cellular band (˜1.9 GHz) for a distributedantenna system, a native frequency, or other frequency for a backhaulsystem. An extractor (or demultiplexer) 1432 can extract the signal on asubcarrier and direct the signal to an output component 1422 foroptional amplification, buffering or isolation by power amplifier 1424for coupling to communications interface 205. The communicationsinterface 205 can further process the signals received from the poweramplifier 1424 or otherwise transmit such signals over a wireless orwired interface to other devices such as a base station, mobile devices,a building, etc. For the signals that are not being extracted at thislocation, extractor 1432 can redirect them to another frequency mixer1436, where the signals are used to modulate a carrier wave generated bylocal oscillator 1414. The carrier wave, with its subcarriers, isdirected to a power amplifier (“PA”) 1416 and is retransmitted bywaveguide coupling device 1404 to another system, via diplexer 1420.

An LNA 1426 can be used to amplify, buffer or isolate signals that arereceived by the communication interface 205 and then send the signal toa multiplexer 1434 which merges the signal with signals that have beenreceived from waveguide coupling device 1404. The signals received fromcoupling device 1404 have been split by diplexer 1420, and then passedthrough LNA 1418, and downshifted in frequency by frequency mixer 1438.When the signals are combined by multiplexer 1434, they are upshifted infrequency by frequency mixer 1430, and then boosted by PA 1410, andtransmitted to another system by waveguide coupling device 1402. In anembodiment bidirectional repeater system can be merely a repeaterwithout the output device 1422. In this embodiment, the multiplexer 1434would not be utilized and signals from LNA 1418 would be directed tomixer 1430 as previously described. It will be appreciated that in someembodiments, the bidirectional repeater system could also be implementedusing two distinct and separate unidirectional repeaters. In analternative embodiment, a bidirectional repeater system could also be abooster or otherwise perform retransmissions without downshifting andupshifting. Indeed in example embodiment, the retransmissions can bebased upon receiving a signal or guided wave and performing some signalor guided wave processing or reshaping, filtering, and/or amplification,prior to retransmission of the signal or guided wave.

Referring now to FIG. 15, a block diagram 1500 illustrating an example,non-limiting embodiment of a guided wave communications system is shown.This diagram depicts an exemplary environment in which a guided wavecommunication system, such as the guided wave communication systempresented in conjunction with FIG. 1, can be used.

To provide network connectivity to additional base station devices, abackhaul network that links the communication cells (e.g., microcellsand macrocells) to network devices of a core network correspondinglyexpands. Similarly, to provide network connectivity to a distributedantenna system, an extended communication system that links base stationdevices and their distributed antennas is desirable. A guided wavecommunication system 1500 such as shown in FIG. 15 can be provided toenable alternative, increased or additional network connectivity and awaveguide coupling system can be provided to transmit and/or receiveguided wave (e.g., surface wave) communications on a transmission mediumsuch as a wire that operates as a single-wire transmission line (e.g., autility line), and that can be used as a waveguide and/or that otherwiseoperates to guide the transmission of an electromagnetic wave.

The guided wave communication system 1500 can comprise a first instanceof a distribution system 1550 that includes one or more base stationdevices (e.g., base station device 1504) that are communicably coupledto a central office 1501 and/or a macrocell site 1502. Base stationdevice 1504 can be connected by a wired (e.g., fiber and/or cable), orby a wireless (e.g., microwave wireless) connection to the macrocellsite 1502 and the central office 1501. A second instance of thedistribution system 1560 can be used to provide wireless voice and dataservices to mobile device 1522 and to residential and/or commercialestablishments 1542 (herein referred to as establishments 1542). System1500 can have additional instances of the distribution systems 1550 and1560 for providing voice and/or data services to mobile devices1522-1524 and establishments 1542 as shown in FIG. 15.

Macrocells such as macrocell site 1502 can have dedicated connections toa mobile network and base station device 1504 or can share and/orotherwise use another connection. Central office 1501 can be used todistribute media content and/or provide internet service provider (ISP)services to mobile devices 1522-1524 and establishments 1542. Thecentral office 1501 can receive media content from a constellation ofsatellites 1530 (one of which is shown in FIG. 15) or other sources ofcontent, and distribute such content to mobile devices 1522-1524 andestablishments 1542 via the first and second instances of thedistribution system 1550 and 1560. The central office 1501 can also becommunicatively coupled to the Internet 1503 for providing internet dataservices to mobile devices 1522-1524 and establishments 1542.

Base station device 1504 can be mounted on, or attached to, utility pole1516. In other embodiments, base station device 1504 can be neartransformers and/or other locations situated nearby a power line. Basestation device 1504 can facilitate connectivity to a mobile network formobile devices 1522 and 1524. Antennas 1512 and 1514, mounted on or nearutility poles 1518 and 1520, respectively, can receive signals from basestation device 1504 and transmit those signals to mobile devices 1522and 1524 over a much wider area than if the antennas 1512 and 1514 werelocated at or near base station device 1504.

It is noted that FIG. 15 displays three utility poles, in each instanceof the distribution systems 1550 and 1560, with one base station device,for purposes of simplicity. In other embodiments, utility pole 1516 canhave more base station devices, and more utility poles with distributedantennas and/or tethered connections to establishments 1542.

A transmission device 1506, such as transmission device 101 or 102presented in conjunction with FIG. 1, can transmit a signal from basestation device 1504 to antennas 1512 and 1514 via utility or powerline(s) that connect the utility poles 1516, 1518, and 1520. To transmitthe signal, radio source and/or transmission device 1506 upconverts thesignal (e.g., via frequency mixing) from base station device 1504 orotherwise converts the signal from the base station device 1504 to amicrowave band signal and the transmission device 1506 launches amicrowave band wave that propagates as a guided wave traveling along theutility line or other wire as described in previous embodiments. Atutility pole 1518, another transmission device 1508 receives the guidedwave (and optionally can amplify it as needed or desired or operate as arepeater to receive it and regenerate it) and sends it forward as aguided wave on the utility line or other wire. The transmission device1508 can also extract a signal from the microwave band guided wave andshift it down in frequency or otherwise convert it to its originalcellular band frequency (e.g., 1.9 GHz or other defined cellularfrequency) or another cellular (or non-cellular) band frequency. Anantenna 1512 can wireless transmit the downshifted signal to mobiledevice 1522. The process can be repeated by transmission device 1510,antenna 1514 and mobile device 1524, as necessary or desirable.

Transmissions from mobile devices 1522 and 1524 can also be received byantennas 1512 and 1514 respectively. The transmission devices 1508 and1510 can upshift or otherwise convert the cellular band signals tomicrowave band and transmit the signals as guided wave (e.g., surfacewave or other electromagnetic wave) transmissions over the power line(s)to base station device 1504.

Media content received by the central office 1501 can be supplied to thesecond instance of the distribution system 1560 via the base stationdevice 1504 for distribution to mobile devices 1522 and establishments1542. The transmission device 1510 can be tethered to the establishments1542 by one or more wired connections or a wireless interface. The oneor more wired connections may include without limitation, a power line,a coaxial cable, a fiber cable, a twisted pair cable, a guided wavetransmission medium or other suitable wired mediums for distribution ofmedia content and/or for providing internet services. In an exampleembodiment, the wired connections from the transmission device 1510 canbe communicatively coupled to one or more very high bit rate digitalsubscriber line (VDSL) modems located at one or more correspondingservice area interfaces (SAIs—not shown) or pedestals, each SAI orpedestal providing services to a portion of the establishments 1542. TheVDSL modems can be used to selectively distribute media content and/orprovide internet services to gateways (not shown) located in theestablishments 1542. The SAIs or pedestals can also be communicativelycoupled to the establishments 1542 over a wired medium such as a powerline, a coaxial cable, a fiber cable, a twisted pair cable, a guidedwave transmission medium or other suitable wired mediums. In otherexample embodiments, the transmission device 1510 can be communicativelycoupled directly to establishments 1542 without intermediate interfacessuch as the SAIs or pedestals.

In another example embodiment, system 1500 can employ diversity paths,where two or more utility lines or other wires are strung between theutility poles 1516, 1518, and 1520 (e.g., for example, two or more wiresbetween poles 1516 and 1520) and redundant transmissions from basestation/macrocell site 1502 are transmitted as guided waves down thesurface of the utility lines or other wires. The utility lines or otherwires can be either insulated or uninsulated, and depending on theenvironmental conditions that cause transmission losses, the couplingdevices can selectively receive signals from the insulated oruninsulated utility lines or other wires. The selection can be based onmeasurements of the signal-to-noise ratio of the wires, or based ondetermined weather/environmental conditions (e.g., moisture detectors,weather forecasts, etc.). The use of diversity paths with system 1500can enable alternate routing capabilities, load balancing, increasedload handling, concurrent bi-directional or synchronous communications,spread spectrum communications, etc.

It is noted that the use of the transmission devices 1506, 1508, and1510 in FIG. 15 are by way of example only, and that in otherembodiments, other uses are possible. For instance, transmission devicescan be used in a backhaul communication system, providing networkconnectivity to base station devices. Transmission devices 1506, 1508,and 1510 can be used in many circumstances where it is desirable totransmit guided wave communications over a wire, whether insulated ornot insulated. Transmission devices 1506, 1508, and 1510 areimprovements over other coupling devices due to no contact or limitedphysical and/or electrical contact with the wires that may carry highvoltages. The transmission device can be located away from the wire(e.g., spaced apart from the wire) and/or located on the wire so long asit is not electrically in contact with the wire, as the dielectric actsas an insulator, allowing for cheap, easy, and/or less complexinstallation. However, as previously noted conducting or non-dielectriccouplers can be employed, for example in configurations where the wirescorrespond to a telephone network, cable television network, broadbanddata service, fiber optic communications system or other networkemploying low voltages or having insulated transmission lines.

It is further noted, that while base station device 1504 and macrocellsite 1502 are illustrated in an embodiment, other network configurationsare likewise possible. For example, devices such as access points orother wireless gateways can be employed in a similar fashion to extendthe reach of other networks such as a wireless local area network, awireless personal area network or other wireless network that operatesin accordance with a communication protocol such as a 802.11 protocol,WIMAX protocol, UltraWideband protocol, Bluetooth protocol, Zigbeeprotocol or other wireless protocol.

Referring now to FIGS. 16A & 16B, block diagrams illustrating anexample, non-limiting embodiment of a system for managing a power gridcommunication system are shown. Considering FIG. 16A, a waveguide system1602 is presented for use in a guided wave communications system, suchas the system presented in conjunction with FIG. 15. The waveguidesystem 1602 can comprise sensors 1604, a power management system 1605, atransmission device 101 or 102 that includes at least one communicationinterface 205, transceiver 210 and coupler 220.

The waveguide system 1602 can be coupled to a power line 1610 forfacilitating guided wave communications in accordance with embodimentsdescribed in the subject disclosure. In an example embodiment, thetransmission device 101 or 102 includes coupler 220 for inducingelectromagnetic waves on a surface of the power line 1610 thatlongitudinally propagate along the surface of the power line 1610 asdescribed in the subject disclosure. The transmission device 101 or 102can also serve as a repeater for retransmitting electromagnetic waves onthe same power line 1610 or for routing electromagnetic waves betweenpower lines 1610 as shown in FIGS. 12-13.

The transmission device 101 or 102 includes transceiver 210 configuredto, for example, up-convert a signal operating at an original frequencyrange to electromagnetic waves operating at, exhibiting, or associatedwith a carrier frequency that propagate along a coupler to inducecorresponding guided electromagnetic waves that propagate along asurface of the power line 1610. A carrier frequency can be representedby a center frequency having upper and lower cutoff frequencies thatdefine the bandwidth of the electromagnetic waves. The power line 1610can be a wire (e.g., single stranded or multi-stranded) having aconducting surface or insulated surface. The transceiver 210 can alsoreceive signals from the coupler 220 and down-convert theelectromagnetic waves operating at a carrier frequency to signals attheir original frequency.

Signals received by the communications interface 205 of transmissiondevice 101 or 102 for up-conversion can include without limitationsignals supplied by a central office 1611 over a wired or wirelessinterface of the communications interface 205, a base station 1614 overa wired or wireless interface of the communications interface 205,wireless signals transmitted by mobile devices 1620 to the base station1614 for delivery over the wired or wireless interface of thecommunications interface 205, signals supplied by in-buildingcommunication devices 1618 over the wired or wireless interface of thecommunications interface 205, and/or wireless signals supplied to thecommunications interface 205 by mobile devices 1612 roaming in awireless communication range of the communications interface 205. Inembodiments where the waveguide system 1602 functions as a repeater,such as shown in FIGS. 12-13, the communications interface 205 may ormay not be included in the waveguide system 1602.

The electromagnetic waves propagating along the surface of the powerline 1610 can be modulated and formatted to include packets or frames ofdata that include a data payload and further include networkinginformation (such as header information for identifying one or moredestination waveguide systems 1602). The networking information may beprovided by the waveguide system 1602 or an originating device such asthe central office 1611, the base station 1614, mobile devices 1620, orin-building devices 1618, or a combination thereof. Additionally, themodulated electromagnetic waves can include error correction data formitigating signal disturbances. The networking information and errorcorrection data can be used by a destination waveguide system 1602 fordetecting transmissions directed to it, and for down-converting andprocessing with error correction data transmissions that include voiceand/or data signals directed to recipient communication devicescommunicatively coupled to the destination waveguide system 1602.

Referring now to the sensors 1604 of the waveguide system 1602, thesensors 1604 can comprise one or more of a temperature sensor 1604 a, adisturbance detection sensor 1604 b, a loss of energy sensor 1604 c, anoise sensor 1604 d, a vibration sensor 1604 e, an environmental (e.g.,weather) sensor 1604 f, and/or an image sensor 1604 g. The temperaturesensor 1604 a can be used to measure ambient temperature, a temperatureof the transmission device 101 or 102, a temperature of the power line1610, temperature differentials (e.g., compared to a setpoint orbaseline, between transmission device 101 or 102 and 1610, etc.), or anycombination thereof. In one embodiment, temperature metrics can becollected and reported periodically to a network management system 1601by way of the base station 1614.

The disturbance detection sensor 1604 b can perform measurements on thepower line 1610 to detect disturbances such as signal reflections, whichmay indicate a presence of a downstream disturbance that may impede thepropagation of electromagnetic waves on the power line 1610. A signalreflection can represent a distortion resulting from, for example, anelectromagnetic wave transmitted on the power line 1610 by thetransmission device 101 or 102 that reflects in whole or in part back tothe transmission device 101 or 102 from a disturbance in the power line1610 located downstream from the transmission device 101 or 102.

Signal reflections can be caused by obstructions on the power line 1610.For example, a tree limb may cause electromagnetic wave reflections whenthe tree limb is lying on the power line 1610, or is in close proximityto the power line 1610 which may cause a corona discharge. Otherobstructions that can cause electromagnetic wave reflections can includewithout limitation an object that has been entangled on the power line1610 (e.g., clothing, a shoe wrapped around a power line 1610 with ashoe string, etc.), a corroded build-up on the power line 1610 or an icebuild-up. Power grid components may also impede or obstruct with thepropagation of electromagnetic waves on the surface of power lines 1610.Illustrations of power grid components that may cause signal reflectionsinclude without limitation a transformer and a joint for connectingspliced power lines. A sharp angle on the power line 1610 may also causeelectromagnetic wave reflections.

The disturbance detection sensor 1604 b can comprise a circuit tocompare magnitudes of electromagnetic wave reflections to magnitudes oforiginal electromagnetic waves transmitted by the transmission device101 or 102 to determine how much a downstream disturbance in the powerline 1610 attenuates transmissions. The disturbance detection sensor1604 b can further comprise a spectral analyzer circuit for performingspectral analysis on the reflected waves. The spectral data generated bythe spectral analyzer circuit can be compared with spectral profiles viapattern recognition, an expert system, curve fitting, matched filteringor other artificial intelligence, classification or comparison techniqueto identify a type of disturbance based on, for example, the spectralprofile that most closely matches the spectral data. The spectralprofiles can be stored in a memory of the disturbance detection sensor1604 b or may be remotely accessible by the disturbance detection sensor1604 b. The profiles can comprise spectral data that models differentdisturbances that may be encountered on power lines 1610 to enable thedisturbance detection sensor 1604 b to identify disturbances locally. Anidentification of the disturbance if known can be reported to thenetwork management system 1601 by way of the base station 1614. Thedisturbance detection sensor 1604 b can also utilize the transmissiondevice 101 or 102 to transmit electromagnetic waves as test signals todetermine a roundtrip time for an electromagnetic wave reflection. Theround trip time measured by the disturbance detection sensor 1604 b canbe used to calculate a distance traveled by the electromagnetic wave upto a point where the reflection takes place, which enables thedisturbance detection sensor 1604 b to calculate a distance from thetransmission device 101 or 102 to the downstream disturbance on thepower line 1610.

The distance calculated can be reported to the network management system1601 by way of the base station 1614. In one embodiment, the location ofthe waveguide system 1602 on the power line 1610 may be known to thenetwork management system 1601, which the network management system 1601can use to determine a location of the disturbance on the power line1610 based on a known topology of the power grid. In another embodiment,the waveguide system 1602 can provide its location to the networkmanagement system 1601 to assist in the determination of the location ofthe disturbance on the power line 1610. The location of the waveguidesystem 1602 can be obtained by the waveguide system 1602 from apre-programmed location of the waveguide system 1602 stored in a memoryof the waveguide system 1602, or the waveguide system 1602 can determineits location using a GPS receiver (not shown) included in the waveguidesystem 1602.

The power management system 1605 provides energy to the aforementionedcomponents of the waveguide system 1602. The power management system1605 can receive energy from solar cells, or from a transformer (notshown) coupled to the power line 1610, or by inductive coupling to thepower line 1610 or another nearby power line. The power managementsystem 1605 can also include a backup battery and/or a super capacitoror other capacitor circuit for providing the waveguide system 1602 withtemporary power. The loss of energy sensor 1604 c can be used to detectwhen the waveguide system 1602 has a loss of power condition and/or theoccurrence of some other malfunction. For example, the loss of energysensor 1604 c can detect when there is a loss of power due to defectivesolar cells, an obstruction on the solar cells that causes them tomalfunction, loss of power on the power line 1610, and/or when thebackup power system malfunctions due to expiration of a backup battery,or a detectable defect in a super capacitor. When a malfunction and/orloss of power occurs, the loss of energy sensor 1604 c can notify thenetwork management system 1601 by way of the base station 1614.

The noise sensor 1604 d can be used to measure noise on the power line1610 that may adversely affect transmission of electromagnetic waves onthe power line 1610. The noise sensor 1604 d can sense unexpectedelectromagnetic interference, noise bursts, or other sources ofdisturbances that may interrupt reception of modulated electromagneticwaves on a surface of a power line 1610. A noise burst can be caused by,for example, a corona discharge, or other source of noise. The noisesensor 1604 d can compare the measured noise to a noise profile obtainedby the waveguide system 1602 from an internal database of noise profilesor from a remotely located database that stores noise profiles viapattern recognition, an expert system, curve fitting, matched filteringor other artificial intelligence, classification or comparisontechnique. From the comparison, the noise sensor 1604 d may identify anoise source (e.g., corona discharge or otherwise) based on, forexample, the noise profile that provides the closest match to themeasured noise. The noise sensor 1604 d can also detect how noiseaffects transmissions by measuring transmission metrics such as biterror rate, packet loss rate, jitter, packet retransmission requests,etc. The noise sensor 1604 d can report to the network management system1601 by way of the base station 1614 the identity of noise sources,their time of occurrence, and transmission metrics, among other things.

The vibration sensor 1604 e can include accelerometers and/or gyroscopesto detect 2D or 3D vibrations on the power line 1610. The vibrations canbe compared to vibration profiles that can be stored locally in thewaveguide system 1602, or obtained by the waveguide system 1602 from aremote database via pattern recognition, an expert system, curvefitting, matched filtering or other artificial intelligence,classification or comparison technique. Vibration profiles can be used,for example, to distinguish fallen trees from wind gusts based on, forexample, the vibration profile that provides the closest match to themeasured vibrations. The results of this analysis can be reported by thevibration sensor 1604 e to the network management system 1601 by way ofthe base station 1614.

The environmental sensor 1604 f can include a barometer for measuringatmospheric pressure, ambient temperature (which can be provided by thetemperature sensor 1604 a), wind speed, humidity, wind direction, andrainfall, among other things. The environmental sensor 1604 f cancollect raw information and process this information by comparing it toenvironmental profiles that can be obtained from a memory of thewaveguide system 1602 or a remote database to predict weather conditionsbefore they arise via pattern recognition, an expert system,knowledge-based system or other artificial intelligence, classificationor other weather modeling and prediction technique. The environmentalsensor 1604 f can report raw data as well as its analysis to the networkmanagement system 1601.

The image sensor 1604 g can be a digital camera (e.g., a charged coupleddevice or CCD imager, infrared camera, etc.) for capturing images in avicinity of the waveguide system 1602. The image sensor 1604 g caninclude an electromechanical mechanism to control movement (e.g., actualposition or focal points/zooms) of the camera for inspecting the powerline 1610 from multiple perspectives (e.g., top surface, bottom surface,left surface, right surface and so on). Alternatively, the image sensor1604 g can be designed such that no electromechanical mechanism isneeded in order to obtain the multiple perspectives. The collection andretrieval of imaging data generated by the image sensor 1604 g can becontrolled by the network management system 1601, or can be autonomouslycollected and reported by the image sensor 1604 g to the networkmanagement system 1601.

Other sensors that may be suitable for collecting telemetry informationassociated with the waveguide system 1602 and/or the power lines 1610for purposes of detecting, predicting and/or mitigating disturbancesthat can impede the propagation of electromagnetic wave transmissions onpower lines 1610 (or any other form of a transmission medium ofelectromagnetic waves) may be utilized by the waveguide system 1602.

Referring now to FIG. 16B, block diagram 1650 illustrates an example,non-limiting embodiment of a system for managing a power grid 1653 and acommunication system 1655 embedded therein or associated therewith inaccordance with various aspects described herein. The communicationsystem 1655 comprises a plurality of waveguide systems 1602 coupled topower lines 1610 of the power grid 1653. At least a portion of thewaveguide systems 1602 used in the communication system 1655 can be indirect communication with a base station 1614 and/or the networkmanagement system 1601. Waveguide systems 1602 not directly connected toa base station 1614 or the network management system 1601 can engage incommunication sessions with either a base station 1614 or the networkmanagement system 1601 by way of other downstream waveguide systems 1602connected to a base station 1614 or the network management system 1601.

The network management system 1601 can be communicatively coupled toequipment of a utility company 1652 and equipment of a communicationsservice provider 1654 for providing each entity, status informationassociated with the power grid 1653 and the communication system 1655,respectively. The network management system 1601, the equipment of theutility company 1652, and the communications service provider 1654 canaccess communication devices utilized by utility company personnel 1656and/or communication devices utilized by communications service providerpersonnel 1658 for purposes of providing status information and/or fordirecting such personnel in the management of the power grid 1653 and/orcommunication system 1655.

FIG. 17A illustrates a flow diagram of an example, non-limitingembodiment of a method 1700 for detecting and mitigating disturbancesoccurring in a communication network of the systems of FIGS. 16A & 16B.Method 1700 can begin with step 1702 where a waveguide system 1602transmits and receives messages embedded in, or forming part of,modulated electromagnetic waves or another type of electromagnetic wavestraveling along a surface of a power line 1610. The messages can bevoice messages, streaming video, and/or other data/information exchangedbetween communication devices communicatively coupled to thecommunication system 1655. At step 1704 the sensors 1604 of thewaveguide system 1602 can collect sensing data. In an embodiment, thesensing data can be collected in step 1704 prior to, during, or afterthe transmission and/or receipt of messages in step 1702. At step 1706the waveguide system 1602 (or the sensors 1604 themselves) can determinefrom the sensing data an actual or predicted occurrence of a disturbancein the communication system 1655 that can affect communicationsoriginating from (e.g., transmitted by) or received by the waveguidesystem 1602. The waveguide system 1602 (or the sensors 1604) can processtemperature data, signal reflection data, loss of energy data, noisedata, vibration data, environmental data, or any combination thereof tomake this determination. The waveguide system 1602 (or the sensors 1604)may also detect, identify, estimate, or predict the source of thedisturbance and/or its location in the communication system 1655. If adisturbance is neither detected/identified nor predicted/estimated atstep 1708, the waveguide system 1602 can proceed to step 1702 where itcontinues to transmit and receive messages embedded in, or forming partof, modulated electromagnetic waves traveling along a surface of thepower line 1610.

If at step 1708 a disturbance is detected/identified orpredicted/estimated to occur, the waveguide system 1602 proceeds to step1710 to determine if the disturbance adversely affects (oralternatively, is likely to adversely affect or the extent to which itmay adversely affect) transmission or reception of messages in thecommunication system 1655. In one embodiment, a duration threshold and afrequency of occurrence threshold can be used at step 1710 to determinewhen a disturbance adversely affects communications in the communicationsystem 1655. For illustration purposes only, assume a duration thresholdis set to 500 ms, while a frequency of occurrence threshold is set to 5disturbances occurring in an observation period of 10 sec. Thus, adisturbance having a duration greater than 500 ms will trigger theduration threshold. Additionally, any disturbance occurring more than 5times in a 10 sec time interval will trigger the frequency of occurrencethreshold.

In one embodiment, a disturbance may be considered to adversely affectsignal integrity in the communication systems 1655 when the durationthreshold alone is exceeded. In another embodiment, a disturbance may beconsidered as adversely affecting signal integrity in the communicationsystems 1655 when both the duration threshold and the frequency ofoccurrence threshold are exceeded. The latter embodiment is thus moreconservative than the former embodiment for classifying disturbancesthat adversely affect signal integrity in the communication system 1655.It will be appreciated that many other algorithms and associatedparameters and thresholds can be utilized for step 1710 in accordancewith example embodiments.

Referring back to method 1700, if at step 1710 the disturbance detectedat step 1708 does not meet the condition for adversely affectedcommunications (e.g., neither exceeds the duration threshold nor thefrequency of occurrence threshold), the waveguide system 1602 mayproceed to step 1702 and continue processing messages. For instance, ifthe disturbance detected in step 1708 has a duration of 1 msec with asingle occurrence in a 10 sec time period, then neither threshold willbe exceeded. Consequently, such a disturbance may be considered ashaving a nominal effect on signal integrity in the communication system1655 and thus would not be flagged as a disturbance requiringmitigation. Although not flagged, the occurrence of the disturbance, itstime of occurrence, its frequency of occurrence, spectral data, and/orother useful information, may be reported to the network managementsystem 1601 as telemetry data for monitoring purposes.

Referring back to step 1710, if on the other hand the disturbancesatisfies the condition for adversely affected communications (e.g.,exceeds either or both thresholds), the waveguide system 1602 canproceed to step 1712 and report the incident to the network managementsystem 1601. The report can include raw sensing data collected by thesensors 1604, a description of the disturbance if known by the waveguidesystem 1602, a time of occurrence of the disturbance, a frequency ofoccurrence of the disturbance, a location associated with thedisturbance, parameters readings such as bit error rate, packet lossrate, retransmission requests, jitter, latency and so on. If thedisturbance is based on a prediction by one or more sensors of thewaveguide system 1602, the report can include a type of disturbanceexpected, and if predictable, an expected time occurrence of thedisturbance, and an expected frequency of occurrence of the predicteddisturbance when the prediction is based on historical sensing datacollected by the sensors 1604 of the waveguide system 1602.

At step 1714, the network management system 1601 can determine amitigation, circumvention, or correction technique, which may includedirecting the waveguide system 1602 to reroute traffic to circumvent thedisturbance if the location of the disturbance can be determined. In oneembodiment, the waveguide coupling device 1402 detecting the disturbancemay direct a repeater such as the one shown in FIGS. 13-14 to connectthe waveguide system 1602 from a primary power line affected by thedisturbance to a secondary power line to enable the waveguide system1602 to reroute traffic to a different transmission medium and avoid thedisturbance. In an embodiment where the waveguide system 1602 isconfigured as a repeater the waveguide system 1602 can itself performthe rerouting of traffic from the primary power line to the secondarypower line. It is further noted that for bidirectional communications(e.g., full or half-duplex communications), the repeater can beconfigured to reroute traffic from the secondary power line back to theprimary power line for processing by the waveguide system 1602.

In another embodiment, the waveguide system 1602 can redirect traffic byinstructing a first repeater situated upstream of the disturbance and asecond repeater situated downstream of the disturbance to redirecttraffic from a primary power line temporarily to a secondary power lineand back to the primary power line in a manner that avoids thedisturbance. It is further noted that for bidirectional communications(e.g., full or half-duplex communications), repeaters can be configuredto reroute traffic from the secondary power line back to the primarypower line.

To avoid interrupting existing communication sessions occurring on asecondary power line, the network management system 1601 may direct thewaveguide system 1602 to instruct repeater(s) to utilize unused timeslot(s) and/or frequency band(s) of the secondary power line forredirecting data and/or voice traffic away from the primary power lineto circumvent the disturbance.

At step 1716, while traffic is being rerouted to avoid the disturbance,the network management system 1601 can notify equipment of the utilitycompany 1652 and/or equipment of the communications service provider1654, which in turn may notify personnel of the utility company 1656and/or personnel of the communications service provider 1658 of thedetected disturbance and its location if known. Field personnel fromeither party can attend to resolving the disturbance at a determinedlocation of the disturbance. Once the disturbance is removed orotherwise mitigated by personnel of the utility company and/or personnelof the communications service provider, such personnel can notify theirrespective companies and/or the network management system 1601 utilizingfield equipment (e.g., a laptop computer, smartphone, etc.)communicatively coupled to network management system 1601, and/orequipment of the utility company and/or the communications serviceprovider. The notification can include a description of how thedisturbance was mitigated and any changes to the power lines 1610 thatmay change a topology of the communication system 1655.

Once the disturbance has been resolved (as determined in decision 1718),the network management system 1601 can direct the waveguide system 1602at step 1720 to restore the previous routing configuration used by thewaveguide system 1602 or route traffic according to a new routingconfiguration if the restoration strategy used to mitigate thedisturbance resulted in a new network topology of the communicationsystem 1655. In another embodiment, the waveguide system 1602 can beconfigured to monitor mitigation of the disturbance by transmitting testsignals on the power line 1610 to determine when the disturbance hasbeen removed. Once the waveguide system 1602 detects an absence of thedisturbance it can autonomously restore its routing configurationwithout assistance by the network management system 1601 if itdetermines the network topology of the communication system 1655 has notchanged, or it can utilize a new routing configuration that adapts to adetected new network topology.

FIG. 17B illustrates a flow diagram of an example, non-limitingembodiment of a method 1750 for detecting and mitigating disturbancesoccurring in a communication network of the system of FIGS. 16A and 16B.In one embodiment, method 1750 can begin with step 1752 where a networkmanagement system 1601 receives from equipment of the utility company1652 or equipment of the communications service provider 1654maintenance information associated with a maintenance schedule. Thenetwork management system 1601 can at step 1754 identify from themaintenance information, maintenance activities to be performed duringthe maintenance schedule. From these activities, the network managementsystem 1601 can detect a disturbance resulting from the maintenance(e.g., scheduled replacement of a power line 1610, scheduled replacementof a waveguide system 1602 on the power line 1610, scheduledreconfiguration of power lines 1610 in the power grid 1653, etc.).

In another embodiment, the network management system 1601 can receive atstep 1755 telemetry information from one or more waveguide systems 1602.The telemetry information can include among other things an identity ofeach waveguide system 1602 submitting the telemetry information,measurements taken by sensors 1604 of each waveguide system 1602,information relating to predicted, estimated, or actual disturbancesdetected by the sensors 1604 of each waveguide system 1602, locationinformation associated with each waveguide system 1602, an estimatedlocation of a detected disturbance, an identification of thedisturbance, and so on. The network management system 1601 can determinefrom the telemetry information a type of disturbance that may be adverseto operations of the waveguide, transmission of the electromagneticwaves along the wire surface, or both. The network management system1601 can also use telemetry information from multiple waveguide systems1602 to isolate and identify the disturbance. Additionally, the networkmanagement system 1601 can request telemetry information from waveguidesystems 1602 in a vicinity of an affected waveguide system 1602 totriangulate a location of the disturbance and/or validate anidentification of the disturbance by receiving similar telemetryinformation from other waveguide systems 1602.

In yet another embodiment, the network management system 1601 canreceive at step 1756 an unscheduled activity report from maintenancefield personnel. Unscheduled maintenance may occur as result of fieldcalls that are unplanned or as a result of unexpected field issuesdiscovered during field calls or scheduled maintenance activities. Theactivity report can identify changes to a topology configuration of thepower grid 1653 resulting from field personnel addressing discoveredissues in the communication system 1655 and/or power grid 1653, changesto one or more waveguide systems 1602 (such as replacement or repairthereof), mitigation of disturbances performed if any, and so on.

At step 1758, the network management system 1601 can determine fromreports received according to steps 1752 through 1756 if a disturbancewill occur based on a maintenance schedule, or if a disturbance hasoccurred or is predicted to occur based on telemetry data, or if adisturbance has occurred due to an unplanned maintenance identified in afield activity report. From any of these reports, the network managementsystem 1601 can determine whether a detected or predicted disturbancerequires rerouting of traffic by the affected waveguide systems 1602 orother waveguide systems 1602 of the communication system 1655.

When a disturbance is detected or predicted at step 1758, the networkmanagement system 1601 can proceed to step 1760 where it can direct oneor more waveguide systems 1602 to reroute traffic to circumvent thedisturbance. When the disturbance is permanent due to a permanenttopology change of the power grid 1653, the network management system1601 can proceed to step 1770 and skip steps 1762, 1764, 1766, and 1772.At step 1770, the network management system 1601 can direct one or morewaveguide systems 1602 to use a new routing configuration that adapts tothe new topology. However, when the disturbance has been detected fromtelemetry information supplied by one or more waveguide systems 1602,the network management system 1601 can notify maintenance personnel ofthe utility company 1656 or the communications service provider 1658 ofa location of the disturbance, a type of disturbance if known, andrelated information that may be helpful to such personnel to mitigatethe disturbance. When a disturbance is expected due to maintenanceactivities, the network management system 1601 can direct one or morewaveguide systems 1602 to reconfigure traffic routes at a given schedule(consistent with the maintenance schedule) to avoid disturbances causedby the maintenance activities during the maintenance schedule.

Returning back to step 1760 and upon its completion, the process cancontinue with step 1762. At step 1762, the network management system1601 can monitor when the disturbance(s) have been mitigated by fieldpersonnel. Mitigation of a disturbance can be detected at step 1762 byanalyzing field reports submitted to the network management system 1601by field personnel over a communications network (e.g., cellularcommunication system) utilizing field equipment (e.g., a laptop computeror handheld computer/device). If field personnel have reported that adisturbance has been mitigated, the network management system 1601 canproceed to step 1764 to determine from the field report whether atopology change was required to mitigate the disturbance. A topologychange can include rerouting a power line 1610, reconfiguring awaveguide system 1602 to utilize a different power line 1610, otherwiseutilizing an alternative link to bypass the disturbance and so on. If atopology change has taken place, the network management system 1601 candirect at step 1770 one or more waveguide systems 1602 to use a newrouting configuration that adapts to the new topology.

If, however, a topology change has not been reported by field personnel,the network management system 1601 can proceed to step 1766 where it candirect one or more waveguide systems 1602 to send test signals to test arouting configuration that had been used prior to the detecteddisturbance(s). Test signals can be sent to affected waveguide systems1602 in a vicinity of the disturbance. The test signals can be used todetermine if signal disturbances (e.g., electromagnetic wavereflections) are detected by any of the waveguide systems 1602. If thetest signals confirm that a prior routing configuration is no longersubject to previously detected disturbance(s), then the networkmanagement system 1601 can at step 1772 direct the affected waveguidesystems 1602 to restore a previous routing configuration. If, however,test signals analyzed by one or more waveguide coupling device 1402 andreported to the network management system 1601 indicate that thedisturbance(s) or new disturbance(s) are present, then the networkmanagement system 1601 will proceed to step 1768 and report thisinformation to field personnel to further address field issues. Thenetwork management system 1601 can in this situation continue to monitormitigation of the disturbance(s) at step 1762.

In the aforementioned embodiments, the waveguide systems 1602 can beconfigured to be self-adapting to changes in the power grid 1653 and/orto mitigation of disturbances. That is, one or more affected waveguidesystems 1602 can be configured to self-monitor mitigation ofdisturbances and reconfigure traffic routes without requiringinstructions to be sent to them by the network management system 1601.In this embodiment, the one or more waveguide systems 1602 that areself-configurable can inform the network management system 1601 of itsrouting choices so that the network management system 1601 can maintaina macro-level view of the communication topology of the communicationsystem 1655.

While for purposes of simplicity of explanation, the respectiveprocesses are shown and described as a series of blocks in FIGS. 17A and17B, respectively, it is to be understood and appreciated that theclaimed subject matter is not limited by the order of the blocks, assome blocks may occur in different orders and/or concurrently with otherblocks from what is depicted and described herein. Moreover, not allillustrated blocks may be required to implement the methods describedherein.

Turning now to FIG. 18A, a block diagram illustrating an example,non-limiting embodiment of a transmission medium 1800 for propagatingguided electromagnetic waves is shown. In particular, a further exampleof transmission medium 125 presented in conjunction with FIG. 1 ispresented. In an embodiment, the transmission medium 1800 can comprise afirst dielectric material 1802 and a second dielectric material 1804disposed thereon. In an embodiment, the first dielectric material 1802can comprise a dielectric core (referred to herein as dielectric core1802) and the second dielectric material 1804 can comprise a cladding orshell such as a dielectric foam that surrounds in whole or in part thedielectric core (referred to herein as dielectric foam 1804). In anembodiment, the dielectric core 1802 and dielectric foam 1804 can becoaxially aligned to each other (although not necessary). In anembodiment, the combination of the dielectric core 1802 and thedielectric foam 1804 can be flexed or bent at least by 45 degreeswithout damaging the materials of the dielectric core 1802 and thedielectric foam 1804. In an embodiment, an outer surface of thedielectric foam 1804 can be further surrounded in whole or in part by athird dielectric material 1806, which can serve as an outer jacket(referred to herein as jacket 1806). The jacket 1806 can preventexposure of the dielectric core 1802 and the dielectric foam 1804 to anenvironment that can adversely affect the propagation of electromagneticwaves (e.g., water, soil, etc.).

The dielectric core 1802 can comprise, for example, a high densitypolyethylene material, a high density polyurethane material, or othersuitable dielectric material(s). The dielectric foam 1804 can comprise,for example, a cellular plastic material such an expanded polyethylenematerial, or other suitable dielectric material(s). The jacket 1806 cancomprise, for example, a polyethylene material or equivalent. In anembodiment, the dielectric constant of the dielectric foam 1804 can be(or substantially) lower than the dielectric constant of the dielectriccore 1802. For example, the dielectric constant of the dielectric core1802 can be approximately 2.3 while the dielectric constant of thedielectric foam 1804 can be approximately 1.15 (slightly higher than thedielectric constant of air).

The dielectric core 1802 can be used for receiving signals in the formof electromagnetic waves from a launcher or other coupling devicedescribed herein which can be configured to launch guidedelectromagnetic waves on the transmission medium 1800. In oneembodiment, the transmission 1800 can be coupled to a hollow waveguide1808 structured as, for example, a circular waveguide 1809, which canreceive electromagnetic waves from a radiating device such as a stubantenna (not shown). The hollow waveguide 1808 can in turn induce guidedelectromagnetic waves in the dielectric core 1802. In thisconfiguration, the guided electromagnetic waves are guided by or boundto the dielectric core 1802 and propagate longitudinally along thedielectric core 1802. By adjusting electronics of the launcher, anoperating frequency of the electromagnetic waves can be chosen such thata field intensity profile 1810 of the guided electromagnetic wavesextends nominally (or not at all) outside of the jacket 1806.

By maintaining most (if not all) of the field strength of the guidedelectromagnetic waves within portions of the dielectric core 1802, thedielectric foam 1804 and/or the jacket 1806, the transmission medium1800 can be used in hostile environments without adversely affecting thepropagation of the electromagnetic waves propagating therein. Forexample, the transmission medium 1800 can be buried in soil with no (ornearly no) adverse effect to the guided electromagnetic wavespropagating in the transmission medium 1800. Similarly, the transmissionmedium 1800 can be exposed to water (e.g., rain or placed underwater)with no (or nearly no) adverse effect to the guided electromagneticwaves propagating in the transmission medium 1800. In an embodiment, thepropagation loss of guided electromagnetic waves in the foregoingembodiments can be 1 to 2 dB per meter or better at an operatingfrequency of 60 GHz. Depending on the operating frequency of the guidedelectromagnetic waves and/or the materials used for the transmissionmedium 1800 other propagation losses may be possible. Additionally,depending on the materials used to construct the transmission medium1800, the transmission medium 1800 can in some embodiments be flexedlaterally with no (or nearly no) adverse effect to the guidedelectromagnetic waves propagating through the dielectric core 1802 andthe dielectric foam 1804.

FIG. 18B depicts a transmission medium 1820 that differs from thetransmission medium 1800 of FIG. 18A, yet provides a further example ofthe transmission medium 125 presented in conjunction with FIG. 1. Thetransmission medium 1820 shows similar reference numerals for similarelements of the transmission medium 1800 of FIG. 18A. In contrast to thetransmission medium 1800, the transmission medium 1820 comprises aconductive core 1822 having an insulation layer 1823 surrounding theconductive core 1822 in whole or in part. The combination of theinsulation layer 1823 and the conductive core 1822 will be referred toherein as an insulated conductor 1825. In the illustration of FIG. 18B,the insulation layer 1823 is covered in whole or in part by a dielectricfoam 1804 and jacket 1806, which can be constructed from the materialspreviously described. In an embodiment, the insulation layer 1823 cancomprise a dielectric material, such as polyethylene, having a higherdielectric constant than the dielectric foam 1804 (e.g., 2.3 and 1.15,respectively). In an embodiment, the components of the transmissionmedium 1820 can be coaxially aligned (although not necessary). In anembodiment, a hollow waveguide 1808 having metal plates 1809, which canbe separated from the insulation layer 1823 (although not necessary) canbe used to launch guided electromagnetic waves that substantiallypropagate on an outer surface of the insulation layer 1823, howeverother coupling devices as described herein can likewise be employed. Inan embodiment, the guided electromagnetic waves can be sufficientlyguided by or bound by the insulation layer 1823 to guide theelectromagnetic waves longitudinally along the insulation layer 1823. Byadjusting operational parameters of the launcher, an operating frequencyof the guided electromagnetic waves launched by the hollow waveguide1808 can generate an electric field intensity profile 1824 that resultsin the guided electromagnetic waves being substantially confined withinthe dielectric foam 1804 thereby preventing the guided electromagneticwaves from being exposed to an environment (e.g., water, soil, etc.)that adversely affects propagation of the guided electromagnetic wavesvia the transmission medium 1820.

FIG. 18C depicts a transmission medium 1830 that differs from thetransmission mediums 1800 and 1820 of FIGS. 18A and 18B, yet provides afurther example of the transmission medium 125 presented in conjunctionwith FIG. 1. The transmission medium 1830 shows similar referencenumerals for similar elements of the transmission mediums 1800 and 1820of FIGS. 18A and 18B, respectively. In contrast to the transmissionmediums 1800 and 1820, the transmission medium 1830 comprises a bare (oruninsulated) conductor 1832 surrounded in whole or in part by thedielectric foam 1804 and the jacket 1806, which can be constructed fromthe materials previously described. In an embodiment, the components ofthe transmission medium 1830 can be coaxially aligned (although notnecessary). In an embodiment, a hollow waveguide 1808 having metalplates 1809 coupled to the bare conductor 1832 can be used to launchguided electromagnetic waves that substantially propagate on an outersurface of the bare conductor 1832, however other coupling devicesdescribed herein can likewise be employed. In an embodiment, the guidedelectromagnetic waves can be sufficiently guided by or bound by the bareconductor 1832 to guide the guided electromagnetic waves longitudinallyalong the bare conductor 1832. By adjusting operational parameters ofthe launcher, an operating frequency of the guided electromagnetic waveslaunched by the hollow waveguide 1808 can generate an electric fieldintensity profile 1834 that results in the guided electromagnetic wavesbeing substantially confined within the dielectric foam 1804 therebypreventing the guided electromagnetic waves from being exposed to anenvironment (e.g., water, soil, etc.) that adversely affects propagationof the electromagnetic waves via the transmission medium 1830.

It should be noted that the hollow launcher 1808 used with thetransmission mediums 1800, 1820 and 1830 of FIGS. 18A, 18B and 18C,respectively, can be replaced with other launchers or coupling devices.Additionally, the propagation mode(s) of the electromagnetic waves forany of the foregoing embodiments can be fundamental mode(s), anon-fundamental (or asymmetric) mode(s), or combinations thereof.

FIG. 18D is a block diagram illustrating an example, non-limitingembodiment of bundled transmission media 1836 in accordance with variousaspects described herein. The bundled transmission media 1836 cancomprise a plurality of cables 1838 held in place by a flexible sleeve1839. The plurality of cables 1838 can comprise multiple instances ofcable 1800 of FIG. 18A, multiple instances of cable 1820 of FIG. 18B,multiple instances of cable 1830 of FIG. 18C, or any combinationsthereof. The sleeve 1839 can comprise a dielectric material thatprevents soil, water or other external materials from making contactwith the plurality of cables 1838. In an embodiment, a plurality oflaunchers, each utilizing a transceiver similar to the one depicted inFIG. 10A or other coupling devices described herein, can be adapted toselectively induce a guided electromagnetic wave in each cable, eachguided electromagnetic wave conveys different data (e.g., voice, video,messaging, content, etc.). In an embodiment, by adjusting operationalparameters of each launcher or other coupling device, the electric fieldintensity profile of each guided electromagnetic wave can be fully orsubstantially confined within layers of a corresponding cable 1838 toreduce cross-talk between cables 1838.

In situations where the electric field intensity profile of each guidedelectromagnetic wave is not fully or substantially confined within acorresponding cable 1838, cross-talk of electromagnetic signals canoccur between cables 1838 as illustrated by signal plots associated withtwo cables depicted in FIG. 18E. The plots in FIG. 18E show that when aguided electromagnetic wave is induced on a first cable, the emittedelectric and magnetic fields of the first cable can induce signals onthe second cable, which results in cross-talk. Several mitigationoptions can be used to reduce cross-talk between the cables 1838 of FIG.18D. In an embodiment, an absorption material 1840 that can absorbelectromagnetic fields, such as carbon, can be applied to the cables1838 as shown in FIG. 18F to polarize each guided electromagnetic waveat various polarization states to reduce cross-talk between cables 1838.In another embodiment (not shown), carbon beads can be added to gapsbetween the cables 1838 to reduce cross-talk.

In yet another embodiment (not shown), a diameter of cable 1838 can beconfigured differently to vary a speed of propagation of guidedelectromagnetic waves between the cables 1838 in order to reducecross-talk between cables 1838. In an embodiment (not shown), a shape ofeach cable 1838 can be made asymmetric (e.g., elliptical) to direct theguided electromagnetic fields of each cable 1838 away from each other toreduce cross-talk. In an embodiment (not shown), a filler material suchas dielectric foam can be added between cables 1838 to sufficientlyseparate the cables 1838 to reduce cross-talk therebetween. In anembodiment (not shown), longitudinal carbon strips or swirls can beapplied to on an outer surface of the jacket 1806 of each cable 1838 toreduce radiation of guided electromagnetic waves outside of the jacket1806 and thereby reduce cross-talk between cables 1838. In yet anotherembodiment, each launcher can be configured to launch a guidedelectromagnetic wave having a different frequency, modulation, wavepropagation mode, such as an orthogonal frequency, modulation or mode,to reduce cross-talk between the cables 1838.

In yet another embodiment (not shown), pairs of cables 1838 can betwisted in a helix to reduce cross-talk between the pairs and othercables 1838 in a vicinity of the pairs. In some embodiments, certaincables 1838 can be twisted while other cables 1838 are not twisted toreduce cross-talk between the cables 1838. Additionally, each twistedpair cable 1838 can have different pitches (i.e., different twist rates,such as twists per meter) to further reduce cross-talk between the pairsand other cables 1838 in a vicinity of the pairs. In another embodiment(not shown), launchers or other coupling devices can be configured toinduce guided electromagnetic waves in the cables 1838 havingelectromagnetic fields that extend beyond the jacket 1806 into gapsbetween the cables to reduce cross-talk between the cables 1838. It issubmitted that any one of the foregoing embodiments for mitigatingcross-talk between cables 1838 can be combined to further reducecross-talk therebetween.

FIGS. 18G and 18H are block diagrams illustrating example, non-limitingembodiments of a transmission medium with an inner waveguide inaccordance with various aspects described herein. In an embodiment, atransmission medium 1841 can comprise a core 1842. In one embodiment,the core 1842 can be a dielectric core 1842 (e.g., polyethylene). Inanother embodiment, the core 1842 can be an insulated or uninsulatedconductor. The core 1842 can be surrounded by a shell 1844 comprising adielectric foam (e.g., expanded polyethylene material) having a lowerdielectric constant than the dielectric constant of a dielectric core,or insulation layer of a conductive core. The difference in dielectricconstants enables electromagnetic waves to be bound and guided by thecore 1842. The shell 1844 can be covered by a shell jacket 1845. Theshell jacket 1845 can be made of rigid material (e.g., high densityplastic) or a high tensile strength material (e.g., synthetic fiber). Inan embodiment, the shell jacket 1845 can be used to prevent exposure ofthe shell 1844 and core 1842 from an adverse environment (e.g., water,moisture, soil, etc.). In an embodiment, the shell jacket 1845 can besufficiently rigid to separate an outer surface of the core 1842 from aninner surface of the shell jacket 1845 thereby resulting in alongitudinal gap between the shell jacket 1854 and the core 1842. Thelongitudinal gap can be filled with the dielectric foam of the shell1844.

The transmission medium 1841 can further include a plurality of outerring conductors 1846. The outer ring conductors 1846 can be strands ofconductive material that are woven around the shell jacket 1845, therebycovering the shell jacket 1845 in whole or in part. The outer ringconductors 1846 can serve the function of a power line having a returnelectrical path similar to the embodiments described in the subjectdisclosure for receiving power signals from a source (e.g., atransformer, a power generator, etc.). In one embodiment, the outer ringconductors 1846 can be covered by a cable jacket 1847 to preventexposure of the outer ring conductors 1846 to water, soil, or otherenvironmental factors. The cable jacket 1847 can be made of aninsulating material such as polyethylene. The core 1842 can be used as acenter waveguide for the propagation of electromagnetic waves. A hallowwaveguide launcher 1808, such as the circular waveguide previouslydescribed, can be used to launch signals that induce electromagneticwaves guided by the core 1842 in ways similar to those described for theembodiments of FIGS. 18A, 18B, and 18C. The electromagnetic waves can beguided by the core 1842 without utilizing the electrical return path ofthe outer ring conductors 1846 or any other electrical return path. Byadjusting electronics of the launcher 1808, an operating frequency ofthe electromagnetic waves can be chosen such that a field intensityprofile of the guided electromagnetic waves extends nominally (or not atall) outside of the shell jacket 1845.

In another embodiment, a transmission medium 1843 can comprise a hollowcore 1842′ surrounded by a shell jacket 1845′. The shell jacket 1845′can have an inner conductive surface or other surface materials thatenable the hollow core 1842′ to be used as a conduit for electromagneticwaves. The shell jacket 1845′ can be covered at least in part with theouter ring conductors 1846 described earlier for conducting a powersignal. In an embodiment, a cable jacket 1847 can be disposed on anouter surface of the outer ring conductors 1846 to prevent exposure ofthe outer ring conductors 1846 to water, soil or other environmentalfactors. A waveguide launcher 1808 can be used to launch electromagneticwaves guided by the hollow core 1842′ and the conductive inner surfaceof the shell jacket 1845′. In an embodiment (not shown) the hollow core1842′ can further include a dielectric foam such as described earlier.

Transmission medium 1841 can represent a multi-purpose cable thatconducts power on the outer ring conductors 1846 utilizing an electricalreturn path and that provides communication services by way of an innerwaveguide comprising a combination of the core 1842, the shell 1844 andthe shell jacket 1845. The inner waveguide can be used for transmittingor receiving electromagnetic waves (without utilizing an electricalreturn path) guided by the core 1842. Similarly, transmission medium1843 can represent a multi-purpose cable that conducts power on theouter ring conductors 1846 utilizing an electrical return path and thatprovides communication services by way of an inner waveguide comprisinga combination of the hollow core 1842′ and the shell jacket 1845′. Theinner waveguide can be used for transmitting or receivingelectromagnetic waves (without utilizing an electrical return path)guided the hollow core 1842′ and the shell jacket 1845′.

It is submitted that embodiments of FIGS. 18G-18H can be adapted to usemultiple inner waveguides surrounded by outer ring conductors 1846. Theinner waveguides can be adapted to use to cross-talk mitigationtechniques described above (e.g., twisted pairs of waveguides,waveguides of different structural dimensions, use of polarizers withinthe shell, use of different wave modes, etc.).

For illustration purposes only, the transmission mediums 1800, 1820,1830 1836, 1841 and 1843 will be referred to herein as a cable 1850 withan understanding that cable 1850 can represent any one of thetransmission mediums described in the subject disclosure, or a bundlingof multiple instances thereof. For illustration purposes only, thedielectric core 1802, insulated conductor 1825, bare conductor 1832,core 1842, or hollow core 1842′ of the transmission mediums 1800, 1820,1830, 1836, 1841 and 1843, respectively, will be referred to herein astransmission core 1852 with an understanding that cable 1850 can utilizethe dielectric core 1802, insulated conductor 1825, bare conductor 1832,core 1842, or hollow core 1842′ of transmission mediums 1800, 1820,1830, 1836, 1841 and/or 1843, respectively.

Turning now to FIGS. 18I and 18J, block diagrams illustrating example,non-limiting embodiments of connector configurations that can be used bycable 1850 are shown. In one embodiment, cable 1850 can be configuredwith a female connection arrangement or a male connection arrangement asdepicted in FIG. 18I. The male configuration on the right of FIG. 18Ican be accomplished by stripping the dielectric foam 1804 (and jacket1806 if there is one) to expose a portion of the transmission core 1852.The female configuration on the left of FIG. 18I can be accomplished byremoving a portion of the transmission core 1852, while maintaining thedielectric foam 1804 (and jacket 1806 if there is one). In an embodimentin which the transmission core 1852 is hollow as described in relationto FIG. 18H, the male portion of the transmission core 1852 canrepresent a hollow core with a rigid outer surface that can slide intothe female arrangement on the left side of FIG. 18I to align the hollowcores together. It is further noted that in the embodiments of FIGS.18G-18H, the outer ring of conductors 1846 can be modified to connectmale and female portions of cable 1850.

Based on the aforementioned embodiments, the two cables 1850 having maleand female connector arrangements can be mated together. A sleeve withan adhesive inner lining or a shrink wrap material (not shown) can beapplied to an area of a joint between cables 1850 to maintain the jointin a fixed position and prevent exposure (e.g., to water, soil, etc.).When the cables 1850 are mated, the transmission core 1852 of one cablewill be in close proximity to the transmission core 1852 of the othercable. Guided electromagnetic waves propagating by way of either thetransmission core 1852 of cables 1850 traveling from either directioncan cross over between the disjoint the transmission cores 1852 whetheror not the transmission cores 1852 touch, whether or not thetransmission cores 1852 are coaxially aligned, and/or whether or notthere is a gap between the transmission cores 1852.

In another embodiment, a splicing device 1860 having female connectorarrangements at both ends can be used to mate cables 1850 having maleconnector arrangements as shown in FIG. 18J. In an alternativeembodiment not shown in FIG. 18J, the splicing device 1860 can beadapted to have male connector arrangements at both ends which can bemated to cables 1850 having female connector arrangements. In anotherembodiment not shown in FIG. 18J, the splicing device 1860 can beadapted to have a male connector arrangement and a female connectorarrangement at opposite ends which can be mated to cables 1850 havingfemale and male connector arrangements, respectively. It is furthernoted that for a transmission core 1852 having a hollow core, the maleand female arrangements described in FIG. 18I can be applied to thesplicing device 1860 whether the ends of the splicing device 1860 areboth male, both female, or a combination thereof.

The foregoing embodiments for connecting cables illustrated in FIGS.18I-18J can be applied to each single instance of cable 1838 of bundledtransmission media 1836. Similarly, the foregoing embodimentsillustrated in FIGS. 18I-18J can be applied to each single instance ofan inner waveguide for a cable 1841 or 1843 having multiple innerwaveguides.

Turning now to FIG. 18K, a block diagram illustrating example,non-limiting embodiments of transmission mediums 1800′, 1800″, 1800′″and 1800″″ for propagating guided electromagnetic waves is shown. In anembodiment, a transmission medium 1800′ can include a core 1801, and adielectric foam 1804′ divided into sections and covered by a jacket 1806as shown in FIG. 18K. The core 1801 can be represented by the dielectriccore 1802 of FIG. 18A, the insulated conductor 1825 of FIG. 18B, or thebare conductor 1832 of FIG. 18C. Each section of dielectric foam 1804′can be separated by a gap (e.g., air, gas, vacuum, or a substance with alow dielectric constant). In an embodiment, the gap separations betweenthe sections of dielectric foam 1804′ can be quasi-random as shown inFIG. 18K, which can be helpful in reducing reflections ofelectromagnetic waves occurring at each section of dielectric foam 1804′as they propagate longitudinally along the core 1801. The sections ofthe dielectric foam 1804′ can be constructed, for example, as washersmade of a dielectric foam having an inner opening for supporting thecore 1801 in a fixed position. For illustration purposes only, thewashers will be referred to herein as washers 1804′. In an embodiment,the inner opening of each washer 1804′ can be coaxially aligned with anaxis of the core 1801. In another embodiment, the inner opening of eachwasher 1804′ can be offset from the axis of the core 1801. In anotherembodiment (not shown), each washer 1804′ can have a variablelongitudinal thickness as shown by differences in thickness of thewashers 1804′.

In an alternative embodiment, a transmission medium 1800″ can include acore 1801, and a strip of dielectric foam 1804″ wrapped around the corein a helix covered by a jacket 1806 as shown in FIG. 18K. Although itmay not be apparent from the drawing shown in FIG. 18K, in an embodimentthe strip of dielectric foam 1804″ can be twisted around the core 1801with variable pitches (i.e., different twist rates) for differentsections of the strip of dielectric foam 1804″. Utilizing variablepitches can help reduce reflections or other disturbances of theelectromagnetic waves occurring between areas of the core 1801 notcovered by the strip of dielectric foam 1804″. It is further noted thatthe thickness (diameter) of the strip of dielectric foam 1804″ can besubstantially larger (e.g., 2 or more times larger) than diameter of thecore 1801 shown in FIG. 18K.

In an alternative embodiment, a transmission medium 1800′″ (shown in across-sectional view) can include a non-circular core 1801′ covered by adielectric foam 1804 and jacket 1806. In an embodiment, the non-circularcore 1801′ can have an elliptical structure as shown in FIG. 18K, orother suitable non-circular structure. In another embodiment, thenon-circular core 1801′ can have an asymmetric structure. A non-circularcore 1801′ can be used to polarize the fields of electromagnetic wavesinduced on the non-circular core 1801′. The structure of thenon-circular core 1801′ can help preserve the polarization of theelectromagnetic waves as they propagate along the non-circular core1801′.

In an alternative embodiment, a transmission medium 1800″″ (shown in across-sectional view) can include multiple cores 1801″ (only two coresare shown but more are possible). The multiple cores 1801″ can becovered by a dielectric foam 1804 and jacket 1806. The multiple cores1801″ can be used to polarize the fields of electromagnetic wavesinduced on the multiple cores 1801″. The structure of the multiple cores1801′ can preserve the polarization of the guided electromagnetic wavesas they propagate along the multiple cores 1801″.

It will be appreciated that the embodiments of FIG. 18K can be used tomodify the embodiments of FIGS. 18G-18H. For example, core 1842 or core1842′ can be adapted to utilized sectionalized shells 1804′ with gapstherebetween, or one or more strips of dielectric foam 1804″. Similarly,core 1842 or core 1842′ can be adapted to have a non-circular core 1801′that may have symmetric or asymmetric cross-sectional structure.Additionally, core 1842 or core 1842′ can be adapted to use multiplecores 1801″ in a single inner waveguide, or different numbers of coreswhen multiple inner waveguides are used. Accordingly, any of theembodiments shown in FIG. 18K can be applied singly or in combination tothe embodiments of 18G-18H.

Turning now to FIG. 18L is a block diagram illustrating example,non-limiting embodiments of bundled transmission media to mitigatecross-talk in accordance with various aspects described herein. In anembodiment, a bundled transmission medium 1836′ can include variablecore structures 1803. By varying the structures of cores 1803, fields ofguided electromagnetic waves induced in each of the cores oftransmission medium 1836′ may differ sufficiently to reduce cross-talkbetween cables 1838. In another embodiment, a bundled transmission media1836″ can include a variable number of cores 1803′ per cable 1838. Byvarying the number of cores 1803′ per cable 1838, fields of guidedelectromagnetic waves induced in the one or more cores of transmissionmedium 1836″ may differ sufficiently to reduce cross-talk between cables1838. In another embodiment, the cores 1803 or 1803′ can be of differentmaterials. For example, the cores 1803 or 1803′ can be a dielectric core1802, an insulated conductor core 1825, a bare conductor core 1832, orany combinations thereof.

It is noted that the embodiments illustrated in FIGS. 18A-18D and18F-18H can be modified by and/or combined with some of the embodimentsof FIGS. 18K-18L. It is further noted that one or more of theembodiments illustrated in FIGS. 18K-18L can be combined (e.g., usingsectionalized dielectric foam 1804′ or a helix strip of dielectric foam1804″ with cores 1801′, 1801″, 1803 or 1803′). In some embodimentsguided electromagnetic waves propagating in the transmission mediums1800′, 1800″, 1800′″, and/or 1800″″ of FIG. 18K may experience lesspropagation losses than guided electromagnetic waves propagating in thetransmission mediums 1800, 1820 and 1830 of FIGS. 18A-18C. Additionally,the embodiments illustrated in FIGS. 18K-18L can be adapted to use theconnectivity embodiments illustrated in FIGS. 18I-18J.

Turning now to FIG. 18M, a block diagram illustrating an example,non-limiting embodiment of exposed tapered stubs from the bundledtransmission media 1836 for use as antennas 1855 is shown. Each antenna1855 can serve as a directional antenna for radiating wireless signalsdirected to wireless communication devices or for inducingelectromagnetic wave propagation on a surface of a transmission medium(e.g., a power line). In an embodiment, the wireless signals radiated bythe antennas 1855 can be beam steered by adapting the phase and/or othercharacteristics of the wireless signals generated by each antenna 1855.In an embodiment, the antennas 1855 can individually be placed in apie-pan antenna assembly for directing wireless signals in variousdirections.

It is further noted that the terms “core”, “cladding”, “shell”, and“foam” as utilized in the subject disclosure can comprise any types ofmaterials (or combinations of materials) that enable electromagneticwaves to remain bound to the core while propagating longitudinally alongthe core. For example, a strip of dielectric foam 1804″ describedearlier can be replaced with a strip of an ordinary dielectric material(e.g., polyethylene) for wrapping around the dielectric core 1802(referred to herein for illustration purposes only as a “wrap”). In thisconfiguration an average density of the wrap can be small as a result ofair space between sections of the wrap. Consequently, an effectivedielectric constant of the wrap can be less than the dielectric constantof the dielectric core 1802, thereby enabling guided electromagneticwaves to remain bound to the core. Accordingly, any of the embodimentsof the subject disclosure relating to materials used for core(s) andwrappings about the core(s) can be structurally adapted and/or modifiedwith other dielectric materials that achieve the result of maintainingelectromagnetic waves bound to the core(s) while they propagate alongthe core(s). Additionally, a core in whole or in part as described inany of the embodiments of the subject disclosure can comprise an opaquematerial (e.g., polyethylene). Accordingly, electromagnetic waves guidedand bound to the core will have a non-optical frequency range (e.g.,less than the lowest frequency of visible light).

FIGS. 18N, 18O, 18P, 18Q, 18R, 18S and 18T are block diagramsillustrating example, non-limiting embodiments of a waveguide device fortransmitting or receiving electromagnetic waves in accordance withvarious aspects described herein. In an embodiment, FIG. 18N illustratesa front view of a waveguide device 1865 having a plurality of slots 1863(e.g., openings or apertures) for emitting electromagnetic waves havingradiated electric fields (e-fields) 1861. In an embodiment, the radiatede-fields 1861 of pairs of symmetrically positioned slots 1863 (e.g.,north and south slots of the waveguide 1865) can be directed away fromeach other (i.e., polar opposite radial orientations about the cable1862). While the slots 1863 are shown as having a rectangular shape,other shapes such as other polygons, sector and arc shapes, ellipsoidshapes and other shapes are likewise possible. For illustration purposesonly, the term north will refer to a relative direction as shown in thefigures. All references in the subject disclosure to other directions(e.g., south, east, west, northwest, and so forth) will be relative tonorthern illustration. In an embodiment, to achieve e-fields withopposing orientations at the north and south slots 1863, for example,the north and south slots 1863 can be arranged to have a circumferentialdistance between each other that is approximately one wavelength ofelectromagnetic waves signals supplied to these slots. The waveguide1865 can have a cylindrical cavity in a center of the waveguide 1865 toenable placement of a cable 1862. In one embodiment, the cable 1862 cancomprise an insulated conductor. In another embodiment, the cable 1862can comprise an uninsulated conductor. In yet other embodiments, thecable 1862 can comprise any of the embodiments of a transmission core1852 of cable 1850 previously described.

In one embodiment, the cable 1862 can slide into the cylindrical cavityof the waveguide 1865. In another embodiment, the waveguide 1865 canutilize an assembly mechanism (not shown). The assembly mechanism (e.g.,a hinge or other suitable mechanism that provides a way to open thewaveguide 1865 at one or more locations) can be used to enable placementof the waveguide 1865 on an outer surface of the cable 1862 or otherwiseto assemble separate pieces together to form the waveguide 1865 asshown. According to these and other suitable embodiments, the waveguide1865 can be configured to wrap around the cable 1862 like a collar.

FIG. 18O illustrates a side view of an embodiment of the waveguide 1865.The waveguide 1865 can be adapted to have a hollow rectangular waveguideportion 1867 that receives electromagnetic waves 1866 generated by atransmitter circuit as previously described in the subject disclosure(e.g., see reference 101, 1000 of FIGS. 1 and 10A). The electromagneticwaves 1866 can be distributed by the hollow rectangular waveguideportion 1867 into in a hollow collar 1869 of the waveguide 1865. Therectangular waveguide portion 1867 and the hollow collar 1869 can beconstructed of materials suitable for maintaining the electromagneticwaves within the hollow chambers of these assemblies (e.g., carbon fibermaterials). It should be noted that while the waveguide portion 1867 isshown and described in a hollow rectangular configuration, other shapesand/or other non-hollow configurations can be employed. In particular,the waveguide portion 1867 can have a square or other polygonal crosssection, an arc or sector cross section that is truncated to conform tothe outer surface of the cable 1862, a circular or ellipsoid crosssection or cross sectional shape. In addition, the waveguide portion1867 can be configured as, or otherwise include, a solid dielectricmaterial.

As previously described, the hollow collar 1869 can be configured toemit electromagnetic waves from each slot 1863 with opposite e-fields1861 at pairs of symmetrically positioned slots 1863 and 1863′. In anembodiment, the electromagnetic waves emitted by the combination ofslots 1863 and 1863′ can in turn induce electromagnetic waves 1868 onthat are bound to the cable 1862 for propagation according to afundamental wave mode without other wave modes present—such asnon-fundamental wave modes. In this configuration, the electromagneticwaves 1868 can propagate longitudinally along the cable 1862 to otherdownstream waveguide systems coupled to the cable 1862.

It should be noted that since the hollow rectangular waveguide portion1867 of FIG. 18O is closer to slot 1863 (at the northern position of thewaveguide 1865), slot 1863 can emit electromagnetic waves having astronger magnitude than electromagnetic waves emitted by slot 1863′ (atthe southern position). To reduce magnitude differences between theseslots, slot 1863′ can be made larger than slot 1863. The technique ofutilizing different slot sizes to balance signal magnitudes betweenslots can be applied to any of the embodiments of the subject disclosurerelating to FIGS. 18N, 18O, 18Q, 18S, 18U and 18V—some of which aredescribed below.

In another embodiment, FIG. 18P depicts a waveguide 1865′ that can beconfigured to utilize circuitry such as monolithic microwave integratedcircuits (MMICs) 1870 each coupled to a signal input 1872 (e.g., coaxialcable that provides a communication signal). The signal input 1872 canbe generated by a transmitter circuit as previously described in thesubject disclosure (e.g., see reference 101, 1000 of FIGS. 1 and 10A)adapted to provide electrical signals to the MMICs 1870. Each MMIC 1870can be configured to receive signal 1872 which the MMIC 1870 canmodulate and transmit with a radiating element (e.g., an antenna) toemit electromagnetic waves having radiated e-fields 1861. In oneembodiment, the MMIC's 1870 can be configured to receive the same signal1872, but transmit electromagnetic waves having e-fields 1861 ofopposing orientation. This can be accomplished by configuring one of theMMICs 1870 to transmit electromagnetic waves that are 180 degrees out ofphase with the electromagnetic waves transmitted by the other MMIC 1870.In an embodiment, the combination of the electromagnetic waves emittedby the MMICs 1870 can together induce electromagnetic waves 1868 thatare bound to the cable 1862 for propagation according to a fundamentalwave mode without other wave modes present—such as non-fundamental wavemodes. In this configuration, the electromagnetic waves 1868 canpropagate longitudinally along the cable 1862 to other downstreamwaveguide systems coupled to the cable 1862.

A tapered horn 1880 can be added to the embodiments of FIGS. 18O and 18Pto assist in the inducement of the electromagnetic waves 1868 on cable1862 as depicted in FIGS. 18Q and 18R. In an embodiment where the cable1862 is an uninsulated conductor, the electromagnetic waves induced onthe cable 1862 can have a large radial dimension (e.g., 1 meter). Toenable use of a smaller tapered horn 1880, an insulation layer 1879 canbe applied on a portion of the cable 1862 at or near the cavity asdepicted with hash lines in FIGS. 18Q and 18R. The insulation layer 1879can have a tapered end facing away from the waveguide 1865. The addedinsulation enables the electromagnetic waves 1868 initially launched bythe waveguide 1865 (or 1865′) to be tightly bound to the insulation,which in turn reduces the radial dimension of the electromagnetic fields1868 (e.g., centimeters). As the electromagnetic waves 1868 propagateaway from the waveguide 1865 (1865′) and reach the tapered end of theinsulation layer 1879, the radial dimension of the electromagnetic waves1868 begin to increase eventually achieving the radial dimension theywould have had had the electromagnetic waves 1868 been induced on theuninsulated conductor without an insulation layer. In the illustrationof FIGS. 18Q and 18R the tapered end begins at an end of the taperedhorn 1880. In other embodiments, the tapered end of the insulation layer1879 can begin before or after the end of the tapered horn 1880. Thetapered horn can be metallic or constructed of other conductive materialor constructed of a plastic or other non-conductive material that iscoated or clad with a dielectric layer or doped with a conductivematerial to provide reflective properties similar to a metallic horn.

In an embodiment, cable 1862 can comprise any of the embodiments ofcable 1850 described earlier. In this embodiment, waveguides 1865 and1865′ can be coupled to a transmission core 1852 of cable 1850 asdepicted in FIGS. 18S and 18T. The waveguides 1865 and 1865′ can induce,as previously described, electromagnetic waves 1868 on the transmissioncore 1852 for propagation entirely or partially within inner layers ofcable 1850.

It is noted that for the foregoing embodiments of FIGS. 18Q, 18R, 18Sand 18T, electromagnetic waves 1868 can be bidirectional. For example,electromagnetic waves 1868 of a different operating frequency can bereceived by slots 1863 or MMIC's 1870 of the waveguides 1865 and 1865′,respectively. Once received, the electromagnetic waves can be convertedby a receiver circuit (e.g., see reference 101, 1000 of FIGS. 1 and 10A)for generating a communication signal for processing.

Although not shown, it is further noted that the waveguides 1865 and1865′ can be adapted so that the waveguides 1865 and 1865′ can directelectromagnetic waves 1868 upstream or downstream longitudinally. Forexample, a first tapered horn 1880 coupled to a first instance of awaveguide 1865 or 1865′ can be directed westerly on cable 1862, while asecond tapered horn 1880 coupled to a second instance of a waveguide1865 or 1865′ can be directed easterly on cable 1862. The first andsecond instances of the waveguides 1865 or 1865′ can be coupled so thatin a repeater configuration, signals received by the first waveguide1865 or 1865′ can be provided to the second waveguide 1865 or 1865′ forretransmission in an easterly direction on cable 1862. The repeaterconfiguration just described can also be applied from an easterly towesterly direction on cable 1862.

The waveguide 1865 of FIGS. 18N, 18O, 18Q and 18S can also be configuredto generate electromagnetic fields having only non-fundamental orasymmetric wave modes. FIG. 18U depicts an embodiment of a waveguide1865 that can be adapted to generate electromagnetic fields having onlynon-fundamental wave modes. A median line 1890 represents a separationbetween slots where electrical currents on a backside (not shown) of afrontal plate of the waveguide 1865 change polarity. For example,electrical currents on the backside of the frontal plate correspondingto e-fields that are radially outward (i.e., point away from a centerpoint of cable 1862) can in some embodiments be associated with slotslocated outside of the median line 1890 (e.g., slots 1863A and 1863B).Electrical currents on the backside of the frontal plate correspondingto e-fields that are radially inward (i.e., point towards a center pointof cable 1862) can in some embodiments be associated with slots locatedinside of the median line 1890. The direction of the currents can dependon the operating frequency of the electromagnetic waves 1866 supplied tothe hollow rectangular waveguide portion 1867 (see FIG. 18O) among otherparameters.

For illustration purposes, assume the electromagnetic waves 1866supplied to the hollow rectangular waveguide portion 1867 have anoperating frequency whereby a circumferential distance between slots1863A and 1863B is one full wavelength of the electromagnetic waves1866. In this instance, the e-fields of the electromagnetic wavesemitted by slots 1863A and 1863B point radially outward (i.e., haveopposing orientations). When the electromagnetic waves emitted by slots1863A and 1863B are combined, the resulting electromagnetic waves oncable 1862 will propagate according to the fundamental wave mode. Incontrast, by repositioning one of the slots (e.g., slot 1863B) insidethe media line 1890 (i.e., slot 1863C), slot 1863C will generateelectromagnetic waves that have e-fields that are approximately 180degrees out of phase with the e-fields of the electromagnetic wavesgenerated by slot 1863A. Consequently, the e-field orientations of theelectromagnetic waves generated by slot pairs 1863A and 1863C will besubstantially aligned. The combination of the electromagnetic wavesemitted by slot pairs 1863A and 1863C will thus generate electromagneticwaves that are bound to the cable 1862 for propagation according to anon-fundamental wave mode.

To achieve a reconfigurable slot arrangement, waveguide 1865 can beadapted according to the embodiments depicted in FIG. 18V. Configuration(A) depicts a waveguide 1865 having a plurality of symmetricallypositioned slots. Each of the slots 1863 of configuration (A) can beselectively disabled by blocking the slot with a material (e.g., carbonfiber or metal) to prevent the emission of electromagnetic waves. Ablocked (or disabled) slot 1863 is shown in black, while an enabled (orunblocked) slot 1863 is shown in white. Although not shown, a blockingmaterial can be placed behind (or in front) of the frontal plate of thewaveguide 1865. A mechanism (not shown) can be coupled to the blockingmaterial so that the blocking material can slide in or out of aparticular slot 1863 much like closing or opening a window with a cover.The mechanism can be coupled to a linear motor controllable by circuitryof the waveguide 1865 to selectively enable or disable individual slots1863. With such a mechanism at each slot 1863, the waveguide 1865 can beconfigured to select different configurations of enabled and disabledslots 1863 as depicted in the embodiments of FIG. 18V. Other methods ortechniques for covering or opening slots (e.g., utilizing rotatabledisks behind or in front of the waveguide 1865) can be applied to theembodiments of the subject disclosure.

In one embodiment, the waveguide system 1865 can be configured to enablecertain slots 1863 outside the median line 1890 and disable certainslots 1863 inside the median line 1890 as shown in configuration (B) togenerate fundamental waves. Assume, for example, that thecircumferential distance between slots 1863 outside the median line 1890(i.e., in the northern and southern locations of the waveguide system1865) is one full wavelength. These slots will therefore have electricfields (e-fields) pointing at certain instances in time radially outwardas previously described. In contrast, the slots inside the median line1890 (i.e., in the western and eastern locations of the waveguide system1865) will have a circumferential distance of one-half a wavelengthrelative to either of the slots 1863 outside the median line. Since theslots inside the median line 1890 are half a wavelength apart, suchslots will produce electromagnetic waves having e-fields pointingradially outward. If the western and eastern slots 1863 outside themedian line 1890 had been enabled instead of the western and easternslots inside the median line 1890, then the e-fields emitted by thoseslots would have pointed radially inward, which when combined with theelectric fields of the northern and southern would producenon-fundamental wave mode propagation. Accordingly, configuration (B) asdepicted in FIG. 18V can be used to generate electromagnetic waves atthe northern and southern slots 1863 having e-fields that point radiallyoutward and electromagnetic waves at the western and eastern slots 1863with e-fields that also point radially outward, which when combinedinduce electromagnetic waves on cable 1862 having a fundamental wavemode.

In another embodiment, the waveguide system 1865 can be configured toenable a northerly, southerly, westerly and easterly slots 1863 alloutside the median line 1890, and disable all other slots 1863 as shownin configuration (C). Assuming the circumferential distance between apair of opposing slots (e.g., northerly and southerly, or westerly andeasterly) is a full wavelength apart, then configuration (C) can be usedto generate electromagnetic waves having a non-fundamental wave modewith some e-fields pointing radially outward and other fields pointingradially inward. In yet another embodiment, the waveguide system 1865can be configured to enable a northwesterly slot 1863 outside the medianline 1890, enable a southeasterly slot 1863 inside the median line 1890,and disable all other slots 1863 as shown in configuration (D). Assumingthe circumferential distance between such a pair of slots is a fullwavelength apart, then such a configuration can be used to generateelectromagnetic waves having a non-fundamental wave mode with e-fieldsaligned in a northwesterly direction.

In another embodiment, the waveguide system 1865 can be configured toproduce electromagnetic waves having a non-fundamental wave mode withe-fields aligned in a southwesterly direction. This can be accomplishedby utilizing a different arrangement than used in configuration (D).Configuration (E) can be accomplished by enabling a southwesterly slot1863 outside the median line 1890, enabling a northeasterly slot 1863inside the median line 1890, and disabling all other slots 1863 as shownin configuration (E). Assuming the circumferential distance between sucha pair of slots is a full wavelength apart, then such a configurationcan be used to generate electromagnetic waves having a non-fundamentalwave mode with e-fields aligned in a southwesterly direction.Configuration (E) thus generates a non-fundamental wave mode that isorthogonal to the non-fundamental wave mode of configuration (D).

In yet another embodiment, the waveguide system 1865 can be configuredto generate electromagnetic waves having a fundamental wave mode withe-fields that point radially inward. This can be accomplished byenabling a northerly slot 1863 inside the median line 1890, enabling asoutherly slot 1863 inside the median line 1890, enabling an easterlyslot outside the median 1890, enabling a westerly slot 1863 outside themedian 1890, and disabling all other slots 1863 as shown inconfiguration (F). Assuming the circumferential distance between thenortherly and southerly slots is a full wavelength apart, then such aconfiguration can be used to generate electromagnetic waves having afundamental wave mode with radially inward e-fields. Although the slotsselected in configurations (B) and (F) are different, the fundamentalwave modes generated by configurations (B) and (F) are the same.

It yet another embodiment, e-fields can be manipulated between slots togenerate fundamental or non-fundamental wave modes by varying theoperating frequency of the electromagnetic waves 1866 supplied to thehollow rectangular waveguide portion 1867. For example, assume in theillustration of FIG. 18U that for a particular operating frequency ofthe electromagnetic waves 1866 the circumferential distance between slot1863A and 1863B is one full wavelength of the electromagnetic waves1866. In this instance, the e-fields of electromagnetic waves emitted byslots 1863A and 1863B will point radially outward as shown, and can beused in combination to induce electromagnetic waves on cable 1862 havinga fundamental wave mode. In contrast, the e-fields of electromagneticwaves emitted by slots 1863A and 1863C will be radially aligned (i.e.,pointing northerly) as shown, and can be used in combination to induceelectromagnetic waves on cable 1862 having a non-fundamental wave mode.

Now suppose that the operating frequency of the electromagnetic waves1866 supplied to the hollow rectangular waveguide portion 1867 ischanged so that the circumferential distance between slot 1863A and1863B is one-half a wavelength of the electromagnetic waves 1866. Inthis instance, the e-fields of electromagnetic waves emitted by slots1863A and 1863B will be radially aligned (i.e., point in the samedirection). That is, the e-fields of electromagnetic waves emitted byslot 1863B will point in the same direction as the e-fields ofelectromagnetic waves emitted by slot 1863A. Such electromagnetic wavescan be used in combination to induce electromagnetic waves on cable 1862having a non-fundamental wave mode. In contrast, the e-fields ofelectromagnetic waves emitted by slots 1863A and 1863C will be radiallyoutward (i.e., away from cable 1862), and can be used in combination toinduce electromagnetic waves on cable 1862 having a fundamental wavemode.

In another embodiment, the waveguide 1865′ of FIGS. 18P, 18R and 18T canalso be configured to generate electromagnetic waves having onlynon-fundamental wave modes. This can be accomplished by adding moreMMICs 1870 as depicted in FIG. 18W. Each MMIC 1870 can be configured toreceive the same signal input 1872. However, MMICs 1870 can selectivelybe configured to emit electromagnetic waves having differing phasesusing controllable phase-shifting circuitry in each MMIC 1870. Forexample, the northerly and southerly MMICs 1870 can be configured toemit electromagnetic waves having a 180 degree phase difference, therebyaligning the e-fields either in a northerly or southerly direction. Anycombination of pairs of MMICs 1870 (e.g., westerly and easterly MMICs1870, northwesterly and southeasterly MMICs 1870, northeasterly andsouthwesterly MMICs 1870) can be configured with opposing or alignede-fields. Consequently, waveguide 1865′ can be configured to generateelectromagnetic waves with one or more non-fundamental wave modes,electromagnetic waves with one or more fundamental wave modes, or anycombinations thereof.

It is submitted that it is not necessary to select slots 1863 in pairsto generate electromagnetic waves having a non-fundamental wave mode.For example, electromagnetic waves having a non-fundamental wave modecan be generated by enabling a single slot from the plurality of slotsshown in configuration (A) of FIG. 18V and disabling all other slots.Similarly, a single MMIC 1870 of the MMICs 1870 shown in FIG. 18W can beconfigured to generate electromagnetic waves having a non-fundamentalwave mode while all other MMICs 1870 are not in use or disabled.Likewise other wave modes and wave mode combinations can be induced byenabling other non-null proper subsets of waveguide slots 1863 or theMMICs 1870.

It is further submitted that the e-field arrows shown in FIGS. 18U-18Vare illustrative only and represent a static depiction of e-fields. Inpractice, the electromagnetic waves may have oscillating e-fields, whichat one instance in time point outwardly, and at another instance in timepoint inwardly. For example, in the case of non-fundamental wave modeshaving e-fields that are aligned in one direction (e.g., northerly),such waves may at another instance in time have e-fields that point inan opposite direction (e.g., southerly). Similarly, fundamental wavemodes having e-fields that are radial may at one instance have e-fieldsthat point radially away from the cable 1862 and at another instance intime point radially towards the cable 1862. It is further noted that theembodiments of FIGS. 18U-18W can be adapted to generate electromagneticwaves with one or more non-fundamental wave modes, electromagnetic waveswith one or more fundamental wave modes (e.g., TM00 and HE11 modes), orany combinations thereof. It is further noted that such adaptions can beused in combination with any embodiments described in the subjectdisclosure. It is also noted that the embodiments of FIGS. 18U-18W canbe combined (e.g., slots used in combination with MMICs).

It is further noted that in some embodiments, the waveguide systems 1865and 1865′ of FIGS. 18N-18W may generate combinations of fundamental andnon-fundamental wave modes where one wave mode is dominant over theother. For example, in one embodiment electromagnetic waves generated bythe waveguide systems 1865 and 1865′ of FIGS. 18N-18W may have a weaksignal component that has a non-fundamental wave mode, and asubstantially strong signal component that has a fundamental wave mode.Accordingly, in this embodiment, the electromagnetic waves have asubstantially fundamental wave mode. In another embodimentelectromagnetic waves generated by the waveguide systems 1865 and 1865′of FIGS. 18N-18W may have a weak signal component that has a fundamentalwave mode, and a substantially strong signal component that has anon-fundamental wave mode. Accordingly, in this embodiment, theelectromagnetic waves have a substantially non-fundamental wave mode.Further, a non-dominant wave mode may be generated that propagates onlytrivial distances along the length of the transmission medium.

It is also noted that the waveguide systems 1865 and 1865′ of FIGS.18N-18W can be configured to generate instances of electromagnetic wavesthat have wave modes that can differ from a resulting wave mode or modesof the combined electromagnetic wave. It is further noted that each MMIC1870 of the waveguide system 1865′ of FIG. 18W can be configured togenerate an instance of electromagnetic waves having wavecharacteristics that differ from the wave characteristics of anotherinstance of electromagnetic waves generated by another MMIC 1870. OneMMIC 1870, for example, can generate an instance of an electromagneticwave having a spatial orientation and a phase, frequency, magnitude,electric field orientation, and/or magnetic field orientation thatdiffers from the spatial orientation and phase, frequency, magnitude,electric field orientation, and/or magnetic field orientation of adifferent instance of another electromagnetic wave generated by anotherMMIC 1870. The waveguide system 1865′ can thus be configured to generateinstances of electromagnetic waves having different wave and spatialcharacteristics, which when combined achieve resulting electromagneticwaves having one or more desirable wave modes.

From these illustrations, it is submitted that the waveguide systems1865 and 1865′ of FIGS. 18N-18W can be adapted to generateelectromagnetic waves with one or more selectable wave modes. In oneembodiment, for example, the waveguide systems 1865 and 1865′ can beadapted to select one or more wave modes and generate electromagneticwaves having a single wave mode or multiple wave modes selected andproduced from a process of combining instances of electromagnetic waveshaving one or more configurable wave and spatial characteristics. In anembodiment, for example, parametric information can be stored in alook-up table. Each entry in the look-up table can represent aselectable wave mode. A selectable wave mode can represent a single wavemode, or a combination of wave modes. The combination of wave modes canhave one or dominant wave modes. The parametric information can provideconfiguration information for generating instances of electromagneticwaves for producing resultant electromagnetic waves that have thedesired wave mode.

For example, once a wave mode or modes is selected, the parametricinformation obtained from the look-up table from the entry associatedwith the selected wave mode(s) can be used to identify which of one ormore MMICs 1870 to utilize, and/or their corresponding configurations toachieve electromagnetic waves having the desired wave mode(s). Theparametric information may identify the selection of the one or moreMMICs 1870 based on the spatial orientations of the MMICs 1870, whichmay be required for producing electromagnetic waves with the desiredwave mode. The parametric information can also provide information toconfigure each of the one or more MMICs 1870 with a particular phase,frequency, magnitude, electric field orientation, and/or magnetic fieldorientation which may or may not be the same for each of the selectedMMICs 1870. A look-up table with selectable wave modes and correspondingparametric information can be adapted for configuring the slottedwaveguide system 1865.

In some embodiments, a guided electromagnetic wave can be considered tohave a desired wave mode if the corresponding wave mode propagatesnon-trivial distances on a transmission medium and has a field strengththat is substantially greater in magnitude (e.g., 20 dB higher inmagnitude) than other wave modes that may or may not be desirable. Sucha desired wave mode or modes can be referred to as dominant wave mode(s)with the other wave modes being referred to as non-dominant wave modes.In a similar fashion, a guided electromagnetic wave that is said to besubstantially without the fundamental wave mode has either nofundamental wave mode or a non-dominant fundamental wave mode. A guidedelectromagnetic wave that is said to be substantially without anon-fundamental wave mode has either no non-fundamental wave mode(s) oronly non-dominant non-fundamental wave mode(s). In some embodiments, aguided electromagnetic wave that is said to have only a single wave modeor a selected wave mode may have only one corresponding dominant wavemode.

It is further noted that the embodiments of FIGS. 18U-18W can be appliedto other embodiments of the subject disclosure. For example, theembodiments of FIGS. 18U-18W can be used as alternate embodiments to theembodiments depicted in FIGS. 18N-18T or can be combined with theembodiments depicted in FIGS. 18N-18T.

Turning now to FIGS. 19A and 19B, block diagrams illustrating example,non-limiting embodiments of the cable 1850 of FIG. 18A used for inducingguided electromagnetic waves on power lines supported by utility poles.In one embodiment, as depicted in FIG. 19A, a cable 1850 can be coupledat one end to a microwave apparatus that launches guided electromagneticwaves within one or more inner layers of cable 1850 utilizing, forexample, the hollow waveguide 1808 shown in FIGS. 18A-18C. The microwaveapparatus can utilize a microwave transceiver such as shown in FIG. 10Afor transmitting or receiving signals from cable 1850. The guidedelectromagnetic waves induced in the one or more inner layers of cable1850 can propagate to an exposed stub of the cable 1850 located inside ahorn antenna (shown as a dotted line in FIG. 19A) for radiating theelectromagnetic waves via the horn antenna. The radiated signals fromthe horn antenna in turn can induce guided electromagnetic waves thatpropagate longitudinally on a medium voltage (MV) power line. In oneembodiment, the microwave apparatus can receive AC power from a lowvoltage (e.g., 220V) power line. Alternatively, the horn antenna can bereplaced with a stub antenna as shown in FIG. 19B to induce guidedelectromagnetic waves that propagate longitudinally on the MV power lineor to transmit wireless signals to other antenna system(s).

In alternate embodiments, first and second cables 1850A′ and 1850B′ canbe coupled to the microwave apparatus and to a transformer 1952,respectively, as shown in FIGS. 19A and 19B. The first and second cables1850A′ and 1850B′ can be represented by, for example, cable 1820 orcable 1830 of FIGS. 18B and 18C, respectively, each having a conductivecore. A first end of the conductive core of the first cable 1850A′ canbe coupled to the microwave apparatus for propagating guidedelectromagnetic waves launched therein. A second end of the conductivecore of the first cable 1850A′ can be coupled to a first end of aconductive coil of the transformer 1952 for receiving the guidedelectromagnetic waves propagating in the first cable 1850A′ and forsupplying signals associated therewith to a first end of a second cable1850B′ by way of a second end of the conductive coil of the transformer1952. A second end of the second cable 1850B′ can be coupled to the hornantenna of FIG. 19A or can be exposed as a stub antenna of FIG. 19B forinducing guided electromagnetic waves that propagate longitudinally onthe MV power line.

In an embodiment where cable 1850, 1850A′ and 1850B′ each comprisemultiple instances of transmission mediums 1800, 1820, and/or 1830, apoly-rod structure of antennas 1855 can be formed such as shown in FIG.18K. Each antenna 1855 can be coupled, for example, to a horn antennaassembly as shown in FIG. 19A or a pie-pan antenna assembly (not shown)for radiating multiple wireless signals. Alternatively, the antennas1855 can be used as stub antennas in FIG. 19B. The microwave apparatusof FIGS. 19A-19B can be configured to adjust the guided electromagneticwaves to beam steer the wireless signals emitted by the antennas 1855.One or more of the antennas 1855 can also be used for inducing guidedelectromagnetic waves on a power line.

Turning now to FIG. 19C, a block diagram of an example, non-limitingembodiment of a communication network 1900 in accordance with variousaspects described herein is shown. In one embodiment, for example, thewaveguide system 1602 of FIG. 16A can be incorporated into networkinterface devices (NIDs) such as NIDs 1910 and 1920 of FIG. 19C. A NIDhaving the functionality of waveguide system 1602 can be used to enhancetransmission capabilities between customer premises 1902 (enterprise orresidential) and a pedestal 1904 (sometimes referred to as a servicearea interface or SAI).

In one embodiment, a central office 1930 can supply one or more fibercables 1926 to the pedestal 1904. The fiber cables 1926 can providehigh-speed full-duplex data services (e.g., 1-100 Gbps or higher) tomini-DSLAMs 1924 located in the pedestal 1904. The data services can beused for transport of voice, internet traffic, media content services(e.g., streaming video services, broadcast TV), and so on. In prior artsystems, mini-DSLAMs 1924 typically connect to twisted pair phone lines(e.g., twisted pairs included in category 5e or Cat. 5e unshieldedtwisted-pair (UTP) cables that include an unshielded bundle of twistedpair cables, such as 24 gauge insulated solid wires, surrounded by anouter insulating sheath), which in turn connect to the customer premises1902 directly. In such systems, DSL data rates taper off at 100 Mbps orless due in part to the length of legacy twisted pair cables to thecustomer premises 1902 among other factors.

The embodiments of FIG. 19C, however, are distinct from prior art DSLsystems. In the illustration of FIG. 19C, a mini-DSLAM 1924, forexample, can be configured to connect to NID 1920 via cable 1850 (whichcan represent in whole or in part any of the cable embodiments describedin relation to FIGS. 18A-18D and 18F-18L singly or in combination).Utilizing cable 1850 between customer premises 1902 and a pedestal 1904,enables NIDs 1910 and 1920 to transmit and receive guide electromagneticwaves for uplink and downlink communications. Based on embodimentspreviously described, cable 1850 can be exposed to rain, or can beburied without adversely affecting electromagnetic wave propagationeither in a downlink path or an uplink path so long as the electricfield profile of such waves in either direction is confined at least inpart or entirely within inner layers of cable 1850. In the presentillustration, downlink communications represents a communication pathfrom the pedestal 1904 to customer premises 1902, while uplinkcommunications represents a communication path from customer premises1902 to the pedestal 1904. In an embodiment where cable 1850 comprisesone of the embodiments of FIGS. 18G-18H, cable 1850 can also serve thepurpose of supplying power to the NID 1910 and 1920 and other equipmentof the customer premises 1902 and the pedestal 1904.

In customer premises 1902, DSL signals can originate from a DSL modem1906 (which may have a built-in router and which may provide wirelessservices such as WiFi to user equipment shown in the customer premises1902). The DSL signals can be supplied to NID 1910 by a twisted pairphone 1908. The NID 1910 can utilize the integrated waveguide 1602 tolaunch within cable 1850 guided electromagnetic waves 1914 directed tothe pedestal 1904 on an uplink path. In the downlink path, DSL signalsgenerated by the mini-DSLAM 1924 can flow through a twisted pair phoneline 1922 to NID 1920. The waveguide system 1602 integrated in the NID1920 can convert the DSL signals, or a portion thereof, from electricalsignals to guided electromagnetic waves 1914 that propagate within cable1850 on the downlink path. To provide full duplex communications, theguided electromagnetic waves 1914 on the uplink can be configured tooperate at a different carrier frequency and/or a different modulationapproach than the guided electromagnetic waves 1914 on the downlink toreduce or avoid interference. Additionally, on the uplink and downlinkpaths, the guided electromagnetic waves 1914 are guided by a coresection of cable 1850, as previously described, and such waves can beconfigured to have a field intensity profile that confines the guideelectromagnetic waves in whole or in part in the inner layers of cable1850. Although the guided electromagnetic waves 1914 are shown outsideof cable 1850, the depiction of these waves is for illustration purposesonly. For this reason, the guided electromagnetic waves 1914 are drawnwith “hash marks” to indicate that they are guided by the inner layersof cable 1850.

On the downlink path, the integrated waveguide system 1602 of NID 1910receives the guided electromagnetic waves 1914 generated by NID 1920 andconverts them back to DSL signals conforming to the requirements of theDSL modem 1906. The DSL signals are then supplied to the DSL modem 1906via a set of twisted pair wires of phone line 1908 for processing.Similarly, on the uplink path, the integrated waveguide system 1602 ofNID 1920 receives the guided electromagnetic waves 1914 generated by NID1910 and converts them back to DSL signals conforming to therequirements of the mini-DSLAM 1924. The DSL signals are then suppliedto the mini-DSLAM 1924 via a set of twisted pair wires of phone line1922 for processing. Because of the short length of phone lines 1908 and1922, the DSL modem 1908 and the mini-DSLAM 1924 can send and receiveDSL signals between themselves on the uplink and downlink at very highspeeds (e.g., 1 Gbps to 60 Gbps or more). Consequently, the uplink anddownlink paths can in most circumstances exceed the data rate limits oftraditional DSL communications over twisted pair phone lines.

Typically, DSL devices are configured for asymmetric data rates becausethe downlink path usually supports a higher data rate than the uplinkpath. However, cable 1850 can provide much higher speeds both on thedownlink and uplink paths. With a firmware update, a legacy DSL modem1906 such as shown in FIG. 19C can be configured with higher speeds onboth the uplink and downlink paths. Similar firmware updates can be madeto the mini-DSLAM 1924 to take advantage of the higher speeds on theuplink and downlink paths. Since the interfaces to the DSL modem 1906and mini-DSLAM 1924 remain as traditional twisted pair phone lines, nohardware change is necessary for a legacy DSL modem or legacy mini-DSLAMother than firmware changes and the addition of the NIDs 1910 and 1920to perform the conversion from DSL signals to guided electromagneticwaves 1914 and vice-versa. The use of NIDs enables a reuse of legacymodems 1906 and mini-DSLAMs 1924, which in turn can substantially reduceinstallation costs and system upgrades. For new construction, updatedversions of mini-DSLAMs and DSL modems can be configured with integratedwaveguide systems to perform the functions described above, therebyeliminating the need for NIDs 1910 and 1920 with integrated waveguidesystems. In this embodiment, an updated version of modem 1906 andupdated version of mini-DSLAM 1924 would connect directly to cable 1850and communicate via bidirectional guided electromagnetic wavetransmissions, thereby averting a need for transmission or reception ofDSL signals using twisted pair phone lines 1908 and 1922.

In an embodiment where use of cable 1850 between the pedestal 1904 andcustomer premises 1902 is logistically impractical or costly, NID 1910can be configured instead to couple to a cable 1850′ (similar to cable1850 of the subject disclosure) that originates from a waveguide 108 ona utility pole 118, and which may be buried in soil before it reachesNID 1910 of the customer premises 1902. Cable 1850′ can be used toreceive and transmit guided electromagnetic waves 1914′ between the NID1910 and the waveguide 108. Waveguide 108 can connect via waveguide 106,which can be coupled to base station 104. Base station 104 can providedata communication services to customer premises 1902 by way of itsconnection to central office 1930 over fiber 1926′. Similarly, insituations where access from the central office 1926 to pedestal 1904 isnot practical over a fiber link, but connectivity to base station 104 ispossible via fiber link 1926′, an alternate path can be used to connectto NID 1920 of the pedestal 1904 via cable 1850″ (similar to cable 1850of the subject disclosure) originating from pole 116. Cable 1850″ canalso be buried before it reaches NID 1920.

FIGS. 20A and 20B describe embodiments for downlink and uplinkcommunications. Method 2000 of FIG. 20A can begin with step 2002 whereelectrical signals (e.g., DSL signals) are generated by a DSLAM (e.g.,mini-DSLAM 1924 of pedestal 1904 or from central office 1930), which areconverted to guided electromagnetic waves 1914 at step 2004 by NID 1920and which propagate on a transmission medium such as cable 1850 forproviding downlink services to the customer premises 1902. At step 2008,the NID 1910 of the customer premises 1902 converts the guidedelectromagnetic waves 1914 back to electrical signals (e.g., DSLsignals) which are supplied at step 2010 to customer premises equipment(CPE) such as DSL modem 1906 over phone line 1908. Alternatively, or incombination, power and/or guided electromagnetic waves 1914′ can besupplied from a power line 1850′ of a utility grid (having an innerwaveguide as illustrated in FIG. 18G or 18H) to NID 1910 as an alternateor additional downlink (and/or uplink) path.

At 2022 of method 2020 of FIG. 20B, the DSL modem 1906 can supplyelectrical signals (e.g., DSL signals) via phone line 1908 to NID 1910,which in turn at step 2024, converts the DSL signals to guidedelectromagnetic waves directed to NID 1920 by way of cable 1850. At step2028, the NID 1920 of the pedestal 1904 (or central office 1930)converts the guided electromagnetic waves 1914 back to electricalsignals (e.g., DSL signals) which are supplied at step 2029 to a DSLAM(e.g., mini-DSLAM 1924). Alternatively, or in combination, power andguided electromagnetic waves 1914′ can be supplied from a power line1850′ of a utility grid (having an inner waveguide as illustrated inFIG. 18G or 18H) to NID 1920 as an alternate or additional uplink(and/or downlink) path.

Turning now to FIG. 20C, a flow diagram of an example, non-limitingembodiment of a method 2030 for inducing electromagnetic waves on atransmission medium is shown. At step 2032, the waveguides 1865 and1865′ of FIGS. 18N-18T can be configured to generate firstelectromagnetic waves from a first communication signal (supplied, forexample, by a communication device), and induce at step 2034 the firstelectromagnetic waves with “only” a fundamental wave mode at aninterface of the transmission medium. In an embodiment, the interfacecan be an outer surface of the transmission medium as depicted in FIGS.18Q and 18R. In another embodiment, the interface can be an inner layerof the transmission medium as depicted in FIGS. 18S and 18T. Turning nowto FIG. 20D, a flow diagram of an example, non-limiting embodiment of amethod 2040 for receiving electromagnetic waves from a transmissionmedium is shown. At step 2042, the waveguides 1865 and 1865′ of FIGS.18N-18T can be configured to receive second electromagnetic waves at aninterface of a same or different transmission medium described in FIG.20C. In an embodiment, the second electromagnetic waves can have “only”a fundamental wave mode. In other embodiments, the secondelectromagnetic waves may have a combination of wave modes such as afundamental and non-fundamental wave modes. At step 2044, a secondcommunication signal can be generated from the second electromagneticwaves for processing by, for example, a same or different communicationdevice. The embodiments of FIGS. 20C and 20D can be applied to anyembodiments described in the subject disclosure.

Turning now to FIG. 20E, a flow diagram of an example, non-limitingembodiment of a method 2050 for inducing electromagnetic waves on atransmission medium is shown. At step 2052, the waveguides 1865 and1865′ of FIGS. 18N-18W can be configured to generate firstelectromagnetic waves from a first communication signal (supplied, forexample, by a communication device), and induce at step 2054 secondelectromagnetic waves with “only” a non-fundamental wave mode at aninterface of the transmission medium. In an embodiment, the interfacecan be an outer surface of the transmission medium as depicted in FIGS.18Q and 18R. In another embodiment, the interface can be an inner layerof the transmission medium as depicted in FIGS. 18S and 18T. Turning nowto FIG. 20F, a flow diagram of an example, non-limiting embodiment of amethod 2060 for receiving electromagnetic waves from a transmissionmedium is shown. At step 2062, the waveguides 1865 and 1865′ of FIGS.18N-18W can be configured to receive electromagnetic waves at aninterface of a same or different transmission medium described in FIG.20E. In an embodiment, the electromagnetic waves can have “only” anon-fundamental wave mode. In other embodiments, the electromagneticwaves may have a combination of wave modes such as a fundamental andnon-fundamental wave modes. At step 2064, a second communication signalcan be generated from the electromagnetic waves for processing by, forexample, a same or different communication device. The embodiments ofFIGS. 20E and 20F can be applied to any embodiments described in thesubject disclosure.

While for purposes of simplicity of explanation, the respectiveprocesses are shown and described as a series of blocks in FIGS.20A-20F, it is to be understood and appreciated that the claimed subjectmatter is not limited by the order of the blocks, as some blocks mayoccur in different orders and/or concurrently with other blocks fromwhat is depicted and described herein. Moreover, not all illustratedblocks may be required to implement the methods described herein.

FIG. 20G illustrates a flow diagram of an example, non-limitingembodiment of a method 2070 for detecting and mitigating disturbancesoccurring in a communication network, such as, for example, the systemof FIGS. 16A and 16B. Method 2070 can begin with step 2072 where anetwork element, such as the waveguide system 1602 of FIGS. 16A-16B, canbe configured to monitor degradation of guided electromagnetic waves onan outer surface of a transmission medium, such as power line 1610. Asignal degradation can be detected according to any number of factorsincluding without limitation, a signal magnitude of the guidedelectromagnetic waves dropping below a certain magnitude threshold, asignal to noise ratio (SNR) dropping below a certain SNR threshold, aQuality of Service (QoS) dropping below one or more thresholds, a biterror rate (BER) exceeding a certain BER threshold, a packet loss rate(PLR) exceeding a certain PLR threshold, a ratio of reflectedelectromagnetic waves to forward electromagnetic waves exceeding acertain threshold, an unexpected change or alteration to a wave mode, aspectral change in the guided electromagnetic waves indicating an objector objects are causing a propagation loss or scattering of the guidedelectromagnetic waves (e.g., water accumulation on an outer surface ofthe transmission medium, a splice in the transmission medium, a brokentree limb, etc.), or any combinations thereof. A sensing device such as,the disturbance sensor 1604 b of FIG. 16A, can be adapted to perform oneor more of the above signal measurements and determine thereby whetherthe electromagnetic waves are experiencing signal degradation. Othersensing devices suitable for performing the above measurements arecontemplated by the subject disclosure.

If signal degradation is detected at step 2074, the network element canproceed to step 2076 where it can determine which object or objects maybe causing the degradation, and once detected, report the detectedobject(s) to the network management system 1601 of FIGS. 16A-16B. Objectdetection can be accomplished by spectral analysis or other forms ofsignal analysis, environmental analysis (e.g., barometric readings, raindetection, etc.), or other suitable techniques for detecting foreignobjects that may adversely affect propagation of electromagnetic wavesguided by the transmission medium. For example, the network element canbe configured to generate spectral data derived from an electromagneticwave received by the network element. The network element can thencompare the spectral data to a plurality of spectral profiles stored inits memory. The plurality of spectral profiles can be pre-stored in amemory of the network element, and can be used to characterize oridentify obstructions that may cause a propagation loss or signaldegradation when such obstructions are present on an outer surface ofthe transmission medium.

For example, an accumulation of water on an outer surface of atransmission medium, such as a thin layer of water and/or waterdroplets, may cause a signal degradation in electromagnetic waves guidedby the transmission medium that may be identifiable by a spectralprofile comprising spectral data that models such an obstruction. Thespectral profile can be generated in a controlled environment (such as alaboratory or other suitable testing environment) by collecting andanalyzing spectral data generated by test equipment (e.g., a waveguidesystem with spectrum analysis capabilities) when receivingelectromagnetic waves over an outer surface of a transmission mediumthat has been subjected to water (e.g., simulated rain water). Anobstruction such as water can generate a different spectral signaturethan other obstructions (e.g., a splice between transmission mediums). Aunique spectral signature can be used to identify certain obstructionsover others. With this technique, spectral profiles can be generated forcharacterizing other obstructions such as a fallen tree limb on thetransmission medium, a splice, and so on. In addition to spectralprofiles, thresholds can be generated for different metrics such as SNR,BER, PLR, and so on. These thresholds can be chosen by a serviceprovider according to desired performance measures for a communicationnetwork that utilizing guided electromagnetic waves for transport ofdata. Some obstructions may also be detected by other methods. Forexample, rain water may be detected by a rain detector coupled to anetwork element, fallen tree limbs may be detected by a vibrationdetector coupled to the network element, and so on.

If a network element does not have access to equipment to detect objectsthat may be causing a degradation of electromagnetic waves, then thenetwork element can skip step 2076 and proceed to step 2078 where itnotifies one or more neighboring network elements (e.g., other waveguidesystem(s) 1602 in a vicinity of the network element) of the detectedsignal degradation. If signal degradation is significant, the networkelement can resort to a different medium for communicating withneighboring network element(s), such as, for example, wirelesscommunications. Alternatively, the network element can substantiallyreduce the operating frequency of the guided electromagnetic waves(e.g., from 40 GHz to 1 GHz), or communicate with neighboring networkelements utilizing other guided electromagnetic waves operating at a lowfrequency, such as a control channel (e.g., 1 MHz). A low frequencycontrol channel may be much less susceptible to interference by theobject(s) causing the signal degradation at much higher operatingfrequencies.

Once an alternate means of communication is established between networkelements, at step 2080 the network element and neighboring networkelements can coordinate a process to adjust the guided electromagneticwaves to mitigate the detected signal degradation. The process caninclude, for example, a protocol for choosing which of the networkelements will perform the adjustments to the electromagnetic waves, thefrequency and magnitude of adjustments, and goals to achieve a desiredsignal quality (e.g., QoS, BER, PLR, SNR, etc.). If, for example, theobject causing the signal degradation is water accumulation on the outersurface of the transmission medium, the network elements can beconfigured to adjust a polarization of the electrical fields (e-fields)and/or magnetic fields (h-fields) of the electromagnetic waves to attaina radial alignment of the e-fields as shown in FIG. 20H. In particular,FIG. 20H presents a block diagram 2001 illustrating an example,non-limiting embodiment of an alignment of e-fields of anelectromagnetic wave to mitigate propagation losses due to wateraccumulation on a transmission medium in accordance with various aspectsdescribed herein. In this example, the longitudinal section of a cable,such as an insulated metal cable implementation of transmission medium125, is presented along with field vectors that illustrate the e-fieldsassociated with guided electromagnetic waves that propagate at 40 GHz.Stronger e-fields are presented by darker field vectors relative toweaker e-fields.

In one embodiment, an adjustment in polarization can be accomplished bygenerating a specific wave mode of the electromagnetic waves (e.g.,transverse magnetic (TM) mode, transverse electric (TE) mode, transverseelectromagnetic (TEM) mode, or a hybrid of a TM mode and TE mode alsoknown as an HE mode). Assuming, for example, that the network elementcomprises the waveguide system 1865′ of FIG. 18W, an adjustment in apolarization of e-fields can be accomplished by configuring two or moreMMIC's 1870 to alter a phase, frequency, amplitude or combinationsthereof of the electromagnetic waves generated by each MMIC 1870.Certain adjustments may cause, for example, the e-fields in the regionof the water film shown in FIG. 20H to align perpendicularly to thesurface of the water. Electric fields that are perpendicular (orapproximately perpendicular) to the surface of water will induce weakercurrents in the water film than e-fields parallel to the water film. Byinducing weaker currents, the electromagnetic waves propagatinglongitudinally will experience less propagation loss. Additionally, itis also desirable for the concentration of the e-fields to extend abovethe water film into the air. If the concentration of e-fields in the airremains high and the majority of the total field strength is in the airinstead of being concentrated in the region of the water and theinsulator, then propagation losses will also be reduced. For example,e-fields of electromagnetic waves that are tightly bound to aninsulation layer such as, Goubau waves (or TM00 waves—see block diagram2031 of FIG. 20K), will experience higher propagation losses even thoughthe e-fields may be perpendicular (or radially aligned) to the waterfilm because more of the field strength is concentrated in the region ofthe water.

Accordingly, electromagnetic waves with e-fields perpendicular (orapproximately perpendicular) to a water film having a higher proportionof the field strength in a region of air (i.e., above the water film)will experience less propagation loss than tightly bound electromagneticwaves having more field strength in the insulating or water layers orelectromagnetic waves having e-fields in the direction of propagationwithin the region of the water film that generate greater losses.

FIG. 20H depicts, in a longitudinal view of an insulated conductor,e-field for TM01 electromagnetic waves operating at 40 GHz. FIGS. 20Iand 20J, in contrast, depict cross-sectional views 2011 and 2021,respectively, of the insulated conductor of FIG. 20H illustrating thefield strength of e-fields in the direction of propagation of theelectromagnetic waves (i.e., e-fields directed out of the page of FIGS.20I and 20J). The electromagnetic waves shown in FIGS. 20I and 20J havea TM01 wave mode at 45 GHz and 40 GHz, respectively. FIG. 20I shows thatthe intensity of the e-fields in the direction of propagation of theelectromagnetic waves is high in a region between the outer surface ofthe insulation and the outer surface of the water film (i.e., the regionof the water film). The high intensity is depicted by a light color (thelighter the color the higher the intensity of the e-fields directed outof the page). FIG. 20I illustrates that there is a high concentration ofe-fields polarized longitudinally in the region of the water film, whichcauses high currents in the water film and consequently high propagationlosses. Thus, under certain circumstances, electromagnetic waves at 45GHz (having a TM01 wave mode) are less suitable to mitigate rain wateror other obstructions located on the outer surface of the insulatedconductor.

In contrast, FIG. 20J shows that the intensity of the e-fields in thedirection of propagation of the electromagnetic waves is weaker in theregion of the water film. The lower intensity is depicted by the darkercolor in the region of the water film. The lower intensity is a resultof the e-fields being polarized mostly perpendicular or radial to thewater film. The radially aligned e-fields also are highly concentratedin the region of air as shown in FIG. 20H. Thus, electromagnetic wavesat 40 GHz (having a TM01 wave mode) produce e-fields that induce lesscurrent in the water film than 45 GHz waves with the same wave mode.Accordingly, the electromagnetic waves of FIG. 20J exhibit propertiesmore suitable for reducing propagation losses due to a water film ordroplets accumulating on an outer surface of an insulated conductor.

Since the physical characteristics of a transmission medium can vary,and the effects of water or other obstructions on the outer surface ofthe transmission medium may cause non-linear effects, it may not alwaysbe possible to precisely model all circumstances so as to achieve thee-field polarization and e-field concentration in air depicted in FIG.20H on a first iteration of step 2082. To increase a speed of themitigation process, a network element can be configured to choose from alook-up table at step 2086 a starting point for adjustingelectromagnetic waves. In one embodiment, entries of the look-up tablecan be searched for matches to a type of object detected at step 2076(e.g., rain water). In another embodiment, the look-up table can besearched for matches to spectral data derived from the affectedelectromagnetic wave received by the network elements. Table entries canprovide specific parameters for adjusting electromagnetic waves (e.g.,frequency, phase, amplitude, wave mode, etc.) to achieve at least acoarse adjustment that achieves similar e-field properties as shown inFIG. 20H. A coarse adjustment can serve to improve the likelihood ofconverging on a solution that achieves the desirable propagationproperties previously discussed in relation to FIGS. 20H and 20J.

Once a coarse adjustment is made at step 2086, the network element candetermine at step 2084 whether the adjustment has improved signalquality to a desirable target. Step 2084 can be implemented by acooperative exchange between network elements. For example, suppose thenetwork element at step 2086 generates an adjusted electromagnetic waveaccording to parameters obtained from the look-up table and transmitsthe adjusted electromagnetic wave to a neighboring network element. Atstep 2084 the network element can determine whether the adjustment hasimproved signal quality by receiving feedback from a neighboring networkelement receiving the adjusted electromagnetic waves, analyzing thequality of the received waves according to agreed target goals, andproviding the results to the network element. Similarly, the networkelement can test adjusted electromagnetic waves received fromneighboring network elements and can provide feedback to the neighboringnetwork elements including the results of the analysis. While aparticular search algorithm is discussed above, other search algorithmssuch as a gradient search, genetic algorithm, global search or otheroptimization techniques can likewise be employed. Accordingly, steps2082, 2086 and 2084 represent an adjustment and testing processperformed by the network element and its neighbor(s).

With this in mind, if at step 2084 a network element (or its neighbors)determine that signal quality has not achieved one or more desiredparametric targets (e.g., SNR, BER, PLR, etc.), then incrementaladjustments can begin at step 2082 for each of the network element andits neighbors. At step 2082, the network element (and/or its neighbors)can be configured to adjust a magnitude, phase, frequency, wave modeand/or other tunable features of the electromagnetic waves incrementallyuntil a target goal is achieved. To perform these adjustments, a networkelement (and its neighbors) can be configured with the waveguide system1865′ of FIG. 18W. The network element (and its neighbors) can utilizetwo or more MMIC's 1870 to incrementally adjust one or more operationalparameters of the electromagnetic waves to achieve e-fields polarized ina particular direction (e.g., away from the direction of propagation inthe region of the water film). The two or more MMIC's 1870 can also beconfigured to incrementally adjust one or more operational parameters ofthe electromagnetic waves that achieve e-fields having a highconcentration in a region of air (outside the obstruction).

The iteration process can be a trial-and-error process coordinatedbetween network elements to reduce a time for converging on a solutionthat improves upstream and downstream communications. As part of thecoordination process, for example, one network element can be configuredto adjust a magnitude but not a wave mode of the electromagnetic waves,while another network element can be configured to adjust the wave modeand not the magnitude. The number of iterations and combination ofadjustments to achieve desirable properties in the electromagnetic wavesto mitigate obstructions on an outer surface of a transmission mediumcan be established by a service provider according to experimentationand/or simulations and programmed into the network elements.

Once the network element(s) detect at step 2084 that signal quality ofupstream and downstream electromagnetic waves has improved to adesirable level that achieves one or more parametric targets (e.g. SNR,BER, PLR, etc.), the network elements can proceed to step 2088 andresume communications according to the adjusted upstream and downstreamelectromagnetic waves. While communications take place at step 2088, thenetwork elements can be configured to transmit upstream and downstreamtest signals based on the original electromagnetic waves to determine ifthe signal quality of such waves has improved. These test signals can betransmitted at periodic intervals (e.g., once every 30 seconds or othersuitable periods). Each network element can, for example, analyzespectral data of the received test signals to determine if they achievea desirable spectral profile and/or other parametric target (e.g. SNR,BER, PLR, etc.). If the signal quality has not improved or has improvednominally, the network elements can be configured to continuecommunications at step 2088 utilizing the adjusted upstream anddownstream electromagnetic waves.

If, however, signal quality has improved enough to revert back toutilizing the original electromagnetic waves, then the networkelement(s) can proceed to step 2092 to restore settings (e.g., originalwave mode, original magnitude, original frequency, original phase,original spatial orientation, etc.) that produce the originalelectromagnetic waves. Signal quality may improve as a result of aremoval of the obstruction (e.g., rain water evaporates, field personnelremove a fallen tree limb, etc.). At step 2094, the network elements caninitiate communications utilizing the original electromagnetic waves andperform upstream and downstream tests. If the network elements determineat step 2096 from tests performed at step 2094 that signal quality ofthe original electromagnetic waves is satisfactory, then the networkelements can resume communications with the original electromagneticwaves and proceed to step 2072 and subsequent steps as previouslydescribed.

A successful test can be determined at step 2096 by analyzing testsignals according to parametric targets associated with the originalelectromagnetic waves (e.g., BER, SNR, PLR, etc.). If the testsperformed at step 2094 are determined to be unsuccessful at step 2096,the network element(s) can proceed to steps 2082, 2086 and 2084 aspreviously described. Since a prior adjustment to the upstream anddownstream electromagnetic waves may have already been determinedsuccessfully, the network element(s) can restore the settings used forthe previously adjusted electromagnetic waves. Accordingly, a singleiteration of any one of steps 2082, 2086 and 2084 may be sufficient toreturn to step 2088.

It should be noted that in some embodiments restoring the originalelectromagnetic waves may be desirable if, for example, data throughputwhen using the original electromagnetic waves is better than datathroughput when using the adjusted electromagnetic waves. However, whendata throughput of the adjusted electromagnetic waves is better orsubstantially close to the data throughput of the originalelectromagnetic waves, the network element(s) may instead be configuredto continue from step 2088.

It is also noted that although FIGS. 20H and 20K describe a TM01 wavemode, other wave modes (e.g., HE waves, TE waves, TEM waves, etc.) orcombination of wave modes may achieve the desired effects shown in FIG.20H. Accordingly, a wave mode singly or in combination with one or moreother wave modes may generate electromagnetic waves with e-fieldproperties that reduce propagation losses as described in relation toFIGS. 20H and 20J. Such wave modes are therefore contemplated aspossible wave modes the network elements can be configured to produce.

It is further noted that method 2070 can be adapted to generate at steps2082 or 2086 other wave modes that may not be subject to a cutofffrequency. For example, FIG. 20L depicts a block diagram 2041 of anexample, non-limiting embodiment of electric fields of a hybrid wave inaccordance with various aspects described herein. Waves having an HEmode have linearly polarized e-fields which point away from a directionof propagation of electromagnetic waves and can be perpendicular (orapproximately perpendicular) to a region of obstruction (e.g., waterfilm shown in FIGS. 20H-20J). Waves with an HE mode can be configured togenerate e-fields that extend substantially outside of an outer surfaceof an insulated conductor so that more of the total accumulated fieldstrength is in air. Accordingly, some electromagnetic waves having an HEmode can exhibit properties of a large wave mode with e-fieldsorthogonal or approximately orthogonal to a region of obstruction. Asdescribed earlier, such properties can reduce propagation losses.Electromagnetic waves having an HE mode also have the unique propertythat they do not have a cutoff frequency (i.e., they can operate nearDC) unlike other wave modes which have non-zero cutoff frequencies.

Turning now to FIG. 20M, a block diagram 2051 illustrating an example,non-limiting embodiment of electric field characteristics of a hybridwave versus a Goubau wave in accordance with various aspects describedherein is shown. Diagram 2053 shows a distribution of energy betweenHE11 mode waves and Goubau waves for an insulated conductor. The energyplots of diagram 2053 assume that the amount of power used to generatethe Goubau waves is the same as the HE11 waves (i.e., the area under theenergy curves is the same). In the illustration of diagram 2053, Goubauwaves have a steep drop in power when Goubau waves extend beyond theouter surface of an insulated conductor, while HE11 waves have asubstantially lower drop in power beyond the insulation layer.Consequently, Goubau waves have a higher concentration of energy nearthe insulation layer than HE 11 waves. Diagram 2055 depicts similarGoubau and HE11 energy curves when a water film is present on the outersurface of the insulator. The difference between the energy curves ofdiagrams 2053 and 2055 is that the drop in power for the Goubau and theHE11 energy curves begins on an outer edge of the insulator for diagram2053 and on an outer edge of the water film for diagram 2055. The energycurves diagrams 2053 and 2055, however, depict the same behavior. Thatis, the electric fields of Goubau waves are tightly bound to theinsulation layer, which when exposed to water results in greaterpropagation losses than electric fields of HE11 waves having a higherconcentration outside the insulation layer and the water film. Theseproperties are depicted in the HE11 and Goubau diagrams 2057 and 2059,respectively.

By adjusting an operating frequency of HE11 waves, e-fields of HE11waves can be configured to extend substantially above a thin water filmas shown in block diagram 2061 of FIG. 20N having a greater accumulatedfield strength in areas in the air when compared to fields in theinsulator and a water layer surrounding the outside of the insulator.FIG. 20N depicts a wire having a radius of 1 cm and an insulation radiusof 1.5 cm with a dielectric constant of 2.25. As the operating frequencyof HE11 waves is reduced, the e-fields extend outwardly expanding thesize of the wave mode. At certain operating frequencies (e.g., 3 GHz)the wave mode expansion can be substantially greater than the diameterof the insulated wire and any obstructions that may be present on theinsulated wire.

By having e-fields that are perpendicular to a water film and by placingmost of its energy outside the water film, HE11 waves have lesspropagation loss than Goubau waves when a transmission medium issubjected to water or other obstructions. Although Goubau waves haveradial e-fields which are desirable, the waves are tightly coupled tothe insulation layer, which results in the e-fields being highlyconcentrated in the region of an obstruction. Consequently, Goubau wavesare still subject to high propagation losses when an obstruction such asa water film is present on the outer surface of an insulated conductor.

Turning now to FIGS. 21A and 21B, block diagrams illustrating example,non-limiting embodiments of a waveguide system 2100 for launching hybridwaves in accordance with various aspects described herein is shown. Thewaveguide system 2100 can comprise probes 2102 coupled to a slideable orrotatable mechanism 2104 that enables the probes 2102 to be placed atdifferent positions or orientations relative to an outer surface of aninsulated conductor 2108. The mechanism 2104 can comprise a coaxial feed2106 or other coupling that enables transmission of electromagneticwaves by the probes 2102. The coaxial feed 2106 can be placed at aposition on the mechanism 2104 so that the path difference between theprobes 2102 is one-half a wavelength or some odd integer multiplethereof. When the probes 2102 generate electromagnetic signals ofopposite phase, electromagnetic waves can be induced on the outersurface of the insulated conductor 2108 having a hybrid mode (such as anHE11 mode).

The mechanism 2104 can also be coupled to a motor or other actuator (notshown) for moving the probes 2102 to a desirable position. In oneembodiment, for example, the waveguide system 2100 can comprise acontroller that directs the motor to rotate the probes 2102 (assumingthey are rotatable) to a different position (e.g., east and west) togenerate electromagnetic waves that have a horizontally polarized HE11mode as shown in a block diagram 2200 of FIG. 22. To guide theelectromagnetic waves onto the outer surface of the insulated conductor2108, the waveguide system 2100 can further comprise a tapered horn 2110shown in FIG. 21B. The tapered horn 2110 can be coaxially aligned withthe insulated conductor 2108. To reduce the cross-sectional dimension ofthe tapered horn 2110, an additional insulation layer (not shown) canplaced on the insulated conductor 2108. The additional insulation layercan be similar to the tapered insulation layer 1879 shown in FIGS. 18Qand 18R. The additional insulation layer can have a tapered end thatpoints away from the tapered horn 2110. The tapered insulation layer1879 can reduce a size of an initial electromagnetic wave launchedaccording to an HE11 mode. As the electromagnetic waves propagatetowards the tapered end of the insulation layer, the HE11 mode expandsuntil it reaches its full size as shown in FIG. 22. In otherembodiments, the waveguide system 2100 may not need to use the taperedinsulation layer 1879.

FIG. 22 illustrates that HE11 mode waves can be used to mitigateobstructions such as rain water. For example, suppose that rain waterhas caused a water film to surround an outer surface of the insulatedconductor 2108 as shown in FIG. 22. Further assume that water dropletshave collected at the bottom of the insulated conductor 2108. Asillustrated in FIG. 22, the water film occupies a small fraction of thetotal HE11 wave. Also, by having horizontally polarized HE11 waves, thewater droplets are in a least-intense area of the HE11 waves reducinglosses caused by the droplets. Consequently, the HE11 waves experiencemuch lower propagation losses than Goubau waves or waves having a modethat is tightly coupled to the insulated conductor 2108 and thus greaterenergy in the areas occupied by the water.

It is submitted that the waveguide system 2100 of FIGS. 21A-21B can bereplaced with other waveguide systems of the subject disclosure capableof generating electromagnetic waves having an HE mode. For example, thewaveguide system 1865′ of FIG. 18W can be configured to generateelectromagnetic waves having an HE mode. In an embodiment, two or moreMMIC's 1870 of the waveguide system 1865′ can be configured to generateelectromagnetic waves of opposite phase to generate polarized e-fieldssuch as those present in an HE mode. In another embodiment, differentpairs of MMIC's 1870 can be selected to generate HE waves that arepolarized at different spatial positions (e.g., north and south, westand east, northwest and southeast, northeast and southeast, or othersub-fractional coordinates). Additionally, the waveguide systems ofFIGS. 18N-18W can be configured to launch electromagnetic waves havingan HE mode onto the core 1852 of one or more embodiments of cable 1850suitable for propagating HE mode waves.

Although HE waves can have desirable characteristics for mitigatingobstructions on a transmission medium, it is submitted that certain wavemodes having a cutoff frequency (e.g., TE modes, TM modes, TEM modes orcombinations thereof) may also exhibit waves that are sufficiently largeand have polarized e-fields that are orthogonal (or approximatelyorthogonal) to a region of an obstruction enabling their use formitigating propagation losses caused by the obstruction. Method 2070 canbe adapted, for example, to generate such wave modes from a look-uptable at step 2086. Wave modes having a cutoff frequency that exhibit,for example, a wave mode larger than the obstruction and polarizede-fields perpendicular (or approximately perpendicular) to theobstruction can be determined by experimentation and/or simulation. Oncea combination of parameters (e.g., magnitude, phase, frequency, wavemode(s), spatial positioning, etc.) for generating one or more waveswith cutoff frequencies having low propagation loss properties isdetermined, the parametric results for each wave can be stored in alook-up table in a memory of a waveguide system. Similarly, wave modeswith cutoff frequencies exhibiting properties that reduce propagationlosses can also be generated iteratively by any of the search algorithmspreviously described in the process of steps 2082-2084.

While for purposes of simplicity of explanation, the respectiveprocesses are shown and described as a series of blocks in FIG. 20G, itis to be understood and appreciated that the claimed subject matter isnot limited by the order of the blocks, as some blocks may occur indifferent orders and/or concurrently with other blocks from what isdepicted and described herein. Moreover, not all illustrated blocks maybe required to implement the methods described herein.

Referring now to FIG. 23, there is illustrated a block diagram of acomputing environment in accordance with various aspects describedherein. In order to provide additional context for various embodimentsof the embodiments described herein, FIG. 23 and the followingdiscussion are intended to provide a brief, general description of asuitable computing environment 2300 in which the various embodiments ofthe subject disclosure can be implemented. While the embodiments havebeen described above in the general context of computer-executableinstructions that can run on one or more computers, those skilled in theart will recognize that the embodiments can be also implemented incombination with other program modules and/or as a combination ofhardware and software.

Generally, program modules comprise routines, programs, components, datastructures, etc., that perform particular tasks or implement particularabstract data types. Moreover, those skilled in the art will appreciatethat the inventive methods can be practiced with other computer systemconfigurations, comprising single-processor or multiprocessor computersystems, minicomputers, mainframe computers, as well as personalcomputers, hand-held computing devices, microprocessor-based orprogrammable consumer electronics, and the like, each of which can beoperatively coupled to one or more associated devices.

As used herein, a processing circuit includes processor as well as otherapplication specific circuits such as an application specific integratedcircuit, digital logic circuit, state machine, programmable gate arrayor other circuit that processes input signals or data and that producesoutput signals or data in response thereto. It should be noted thatwhile any functions and features described herein in association withthe operation of a processor could likewise be performed by a processingcircuit.

The terms “first,” “second,” “third,” and so forth, as used in theclaims, unless otherwise clear by context, is for clarity only anddoesn't otherwise indicate or imply any order in time. For instance, “afirst determination,” “a second determination,” and “a thirddetermination,” does not indicate or imply that the first determinationis to be made before the second determination, or vice versa, etc.

The illustrated embodiments of the embodiments herein can be alsopracticed in distributed computing environments where certain tasks areperformed by remote processing devices that are linked through acommunications network. In a distributed computing environment, programmodules can be located in both local and remote memory storage devices.

Computing devices typically comprise a variety of media, which cancomprise computer-readable storage media and/or communications media,which two terms are used herein differently from one another as follows.Computer-readable storage media can be any available storage media thatcan be accessed by the computer and comprises both volatile andnonvolatile media, removable and non-removable media. By way of example,and not limitation, computer-readable storage media can be implementedin connection with any method or technology for storage of informationsuch as computer-readable instructions, program modules, structured dataor unstructured data.

Computer-readable storage media can comprise, but are not limited to,random access memory (RAM), read only memory (ROM), electricallyerasable programmable read only memory (EEPROM), flash memory or othermemory technology, compact disk read only memory (CD-ROM), digitalversatile disk (DVD) or other optical disk storage, magnetic cassettes,magnetic tape, magnetic disk storage or other magnetic storage devicesor other tangible and/or non-transitory media which can be used to storedesired information. In this regard, the terms “tangible” or“non-transitory” herein as applied to storage, memory orcomputer-readable media, are to be understood to exclude onlypropagating transitory signals per se as modifiers and do not relinquishrights to all standard storage, memory or computer-readable media thatare not only propagating transitory signals per se.

Computer-readable storage media can be accessed by one or more local orremote computing devices, e.g., via access requests, queries or otherdata retrieval protocols, for a variety of operations with respect tothe information stored by the medium.

Communications media typically embody computer-readable instructions,data structures, program modules or other structured or unstructureddata in a data signal such as a modulated data signal, e.g., a carrierwave or other transport mechanism, and comprises any informationdelivery or transport media. The term “modulated data signal” or signalsrefers to a signal that has one or more of its characteristics set orchanged in such a manner as to encode information in one or moresignals. By way of example, and not limitation, communication mediacomprise wired media, such as a wired network or direct-wiredconnection, and wireless media such as acoustic, RF, infrared and otherwireless media.

With reference again to FIG. 23, the example environment 2300 fortransmitting and receiving signals via or forming at least part of abase station (e.g., base station devices 1504, macrocell site 1502, orbase stations 1614) or central office (e.g., central office 1501 or1611). At least a portion of the example environment 2300 can also beused for transmission devices 101 or 102. The example environment cancomprise a computer 2302, the computer 2302 comprising a processing unit2304, a system memory 2306 and a system bus 2308. The system bus 2308couple's system components including, but not limited to, the systemmemory 2306 to the processing unit 2304. The processing unit 2304 can beany of various commercially available processors. Dual microprocessorsand other multiprocessor architectures can also be employed as theprocessing unit 2304.

The system bus 2308 can be any of several types of bus structure thatcan further interconnect to a memory bus (with or without a memorycontroller), a peripheral bus, and a local bus using any of a variety ofcommercially available bus architectures. The system memory 2306comprises ROM 2310 and RAM 2312. A basic input/output system (BIOS) canbe stored in a non-volatile memory such as ROM, erasable programmableread only memory (EPROM), EEPROM, which BIOS contains the basic routinesthat help to transfer information between elements within the computer2302, such as during startup. The RAM 2312 can also comprise ahigh-speed RAM such as static RAM for caching data.

The computer 2302 further comprises an internal hard disk drive (HDD)2314 (e.g., EIDE, SATA), which internal hard disk drive 2314 can also beconfigured for external use in a suitable chassis (not shown), amagnetic floppy disk drive (FDD) 2316, (e.g., to read from or write to aremovable diskette 2318) and an optical disk drive 2320, (e.g., readinga CD-ROM disk 2322 or, to read from or write to other high capacityoptical media such as the DVD). The hard disk drive 2314, magnetic diskdrive 2316 and optical disk drive 2320 can be connected to the systembus 2308 by a hard disk drive interface 2324, a magnetic disk driveinterface 2326 and an optical drive interface 2328, respectively. Theinterface 2324 for external drive implementations comprises at least oneor both of Universal Serial Bus (USB) and Institute of Electrical andElectronics Engineers (IEEE) 1394 interface technologies. Other externaldrive connection technologies are within contemplation of theembodiments described herein.

The drives and their associated computer-readable storage media providenonvolatile storage of data, data structures, computer-executableinstructions, and so forth. For the computer 2302, the drives andstorage media accommodate the storage of any data in a suitable digitalformat. Although the description of computer-readable storage mediaabove refers to a hard disk drive (HDD), a removable magnetic diskette,and a removable optical media such as a CD or DVD, it should beappreciated by those skilled in the art that other types of storagemedia which are readable by a computer, such as zip drives, magneticcassettes, flash memory cards, cartridges, and the like, can also beused in the example operating environment, and further, that any suchstorage media can contain computer-executable instructions forperforming the methods described herein.

A number of program modules can be stored in the drives and RAM 2312,comprising an operating system 2330, one or more application programs2332, other program modules 2334 and program data 2336. All or portionsof the operating system, applications, modules, and/or data can also becached in the RAM 2312. The systems and methods described herein can beimplemented utilizing various commercially available operating systemsor combinations of operating systems. Examples of application programs2332 that can be implemented and otherwise executed by processing unit2304 include the diversity selection determining performed bytransmission device 101 or 102.

A user can enter commands and information into the computer 2302 throughone or more wired/wireless input devices, e.g., a keyboard 2338 and apointing device, such as a mouse 2340. Other input devices (not shown)can comprise a microphone, an infrared (IR) remote control, a joystick,a game pad, a stylus pen, touch screen or the like. These and otherinput devices are often connected to the processing unit 2304 through aninput device interface 2342 that can be coupled to the system bus 2308,but can be connected by other interfaces, such as a parallel port, anIEEE 1394 serial port, a game port, a universal serial bus (USB) port,an IR interface, etc.

A monitor 2344 or other type of display device can be also connected tothe system bus 2308 via an interface, such as a video adapter 2346. Itwill also be appreciated that in alternative embodiments, a monitor 2344can also be any display device (e.g., another computer having a display,a smart phone, a tablet computer, etc.) for receiving displayinformation associated with computer 2302 via any communication means,including via the Internet and cloud-based networks. In addition to themonitor 2344, a computer typically comprises other peripheral outputdevices (not shown), such as speakers, printers, etc.

The computer 2302 can operate in a networked environment using logicalconnections via wired and/or wireless communications to one or moreremote computers, such as a remote computer(s) 2348. The remotecomputer(s) 2348 can be a workstation, a server computer, a router, apersonal computer, portable computer, microprocessor-based entertainmentappliance, a peer device or other common network node, and typicallycomprises many or all of the elements described relative to the computer2302, although, for purposes of brevity, only a memory/storage device2350 is illustrated. The logical connections depicted comprisewired/wireless connectivity to a local area network (LAN) 2352 and/orlarger networks, e.g., a wide area network (WAN) 2354. Such LAN and WANnetworking environments are commonplace in offices and companies, andfacilitate enterprise-wide computer networks, such as intranets, all ofwhich can connect to a global communications network, e.g., theInternet.

When used in a LAN networking environment, the computer 2302 can beconnected to the local network 2352 through a wired and/or wirelesscommunication network interface or adapter 2356. The adapter 2356 canfacilitate wired or wireless communication to the LAN 2352, which canalso comprise a wireless AP disposed thereon for communicating with thewireless adapter 2356.

When used in a WAN networking environment, the computer 2302 cancomprise a modem 2358 or can be connected to a communications server onthe WAN 2354 or has other means for establishing communications over theWAN 2354, such as by way of the Internet. The modem 2358, which can beinternal or external and a wired or wireless device, can be connected tothe system bus 2308 via the input device interface 2342. In a networkedenvironment, program modules depicted relative to the computer 2302 orportions thereof, can be stored in the remote memory/storage device2350. It will be appreciated that the network connections shown areexample and other means of establishing a communications link betweenthe computers can be used.

The computer 2302 can be operable to communicate with any wirelessdevices or entities operatively disposed in wireless communication,e.g., a printer, scanner, desktop and/or portable computer, portabledata assistant, communications satellite, any piece of equipment orlocation associated with a wirelessly detectable tag (e.g., a kiosk,news stand, restroom), and telephone. This can comprise WirelessFidelity (Wi-Fi) and BLUETOOTH® wireless technologies. Thus, thecommunication can be a predefined structure as with a conventionalnetwork or simply an ad hoc communication between at least two devices.

Wi-Fi can allow connection to the Internet from a couch at home, a bedin a hotel room or a conference room at work, without wires. Wi-Fi is awireless technology similar to that used in a cell phone that enablessuch devices, e.g., computers, to send and receive data indoors and out;anywhere within the range of a base station. Wi-Fi networks use radiotechnologies called IEEE 802.11 (a, b, g, n, ac, ag etc.) to providesecure, reliable, fast wireless connectivity. A Wi-Fi network can beused to connect computers to each other, to the Internet, and to wirednetworks (which can use IEEE 802.3 or Ethernet). Wi-Fi networks operatein the unlicensed 2.4 and 5 GHz radio bands for example or with productsthat contain both bands (dual band), so the networks can providereal-world performance similar to the basic 10BaseT wired Ethernetnetworks used in many offices.

FIG. 24 presents an example embodiment 2400 of a mobile network platform2410 that can implement and exploit one or more aspects of the disclosedsubject matter described herein. In one or more embodiments, the mobilenetwork platform 2410 can generate and receive signals transmitted andreceived by base stations (e.g., base station devices 1504, macrocellsite 1502, or base stations 1614), central office (e.g., central office1501 or 1611), or transmission device 101 or 102 associated with thedisclosed subject matter. Generally, wireless network platform 2410 cancomprise components, e.g., nodes, gateways, interfaces, servers, ordisparate platforms, that facilitate both packet-switched (PS) (e.g.,internet protocol (IP), frame relay, asynchronous transfer mode (ATM))and circuit-switched (CS) traffic (e.g., voice and data), as well ascontrol generation for networked wireless telecommunication. As anon-limiting example, wireless network platform 2410 can be included intelecommunications carrier networks, and can be considered carrier-sidecomponents as discussed elsewhere herein. Mobile network platform 2410comprises CS gateway node(s) 2422 which can interface CS trafficreceived from legacy networks like telephony network(s) 2440 (e.g.,public switched telephone network (PSTN), or public land mobile network(PLMN)) or a signaling system #7 (SS7) network 2470. Circuit switchedgateway node(s) 2422 can authorize and authenticate traffic (e.g.,voice) arising from such networks. Additionally, CS gateway node(s) 2422can access mobility, or roaming, data generated through SS7 network2470; for instance, mobility data stored in a visited location register(VLR), which can reside in memory 2430. Moreover, CS gateway node(s)2422 interfaces CS-based traffic and signaling and PS gateway node(s)2418. As an example, in a 3GPP UMTS network, CS gateway node(s) 2422 canbe realized at least in part in gateway GPRS support node(s) (GGSN). Itshould be appreciated that functionality and specific operation of CSgateway node(s) 2422, PS gateway node(s) 2418, and serving node(s) 2416,is provided and dictated by radio technology(ies) utilized by mobilenetwork platform 2410 for telecommunication.

In addition to receiving and processing CS-switched traffic andsignaling, PS gateway node(s) 2418 can authorize and authenticatePS-based data sessions with served mobile devices. Data sessions cancomprise traffic, or content(s), exchanged with networks external to thewireless network platform 2410, like wide area network(s) (WANs) 2450,enterprise network(s) 2470, and service network(s) 2480, which can beembodied in local area network(s) (LANs), can also be interfaced withmobile network platform 2410 through PS gateway node(s) 2418. It is tobe noted that WANs 2450 and enterprise network(s) 2460 can embody, atleast in part, a service network(s) like IP multimedia subsystem (IMS).Based on radio technology layer(s) available in technology resource(s)2417, packet-switched gateway node(s) 2418 can generate packet dataprotocol contexts when a data session is established; other datastructures that facilitate routing of packetized data also can begenerated. To that end, in an aspect, PS gateway node(s) 2418 cancomprise a tunnel interface (e.g., tunnel termination gateway (TTG) in3GPP UMTS network(s) (not shown)) which can facilitate packetizedcommunication with disparate wireless network(s), such as Wi-Finetworks.

In embodiment 2400, wireless network platform 2410 also comprisesserving node(s) 2416 that, based upon available radio technologylayer(s) within technology resource(s) 2417, convey the variouspacketized flows of data streams received through PS gateway node(s)2418. It is to be noted that for technology resource(s) 2417 that relyprimarily on CS communication, server node(s) can deliver trafficwithout reliance on PS gateway node(s) 2418; for example, server node(s)can embody at least in part a mobile switching center. As an example, ina 3GPP UMTS network, serving node(s) 2416 can be embodied in servingGPRS support node(s) (SGSN).

For radio technologies that exploit packetized communication, server(s)2414 in wireless network platform 2410 can execute numerous applicationsthat can generate multiple disparate packetized data streams or flows,and manage (e.g., schedule, queue, format . . . ) such flows. Suchapplication(s) can comprise add-on features to standard services (forexample, provisioning, billing, customer support . . . ) provided bywireless network platform 2410. Data streams (e.g., content(s) that arepart of a voice call or data session) can be conveyed to PS gatewaynode(s) 2418 for authorization/authentication and initiation of a datasession, and to serving node(s) 2416 for communication thereafter. Inaddition to application server, server(s) 2414 can comprise utilityserver(s), a utility server can comprise a provisioning server, anoperations and maintenance server, a security server that can implementat least in part a certificate authority and firewalls as well as othersecurity mechanisms, and the like. In an aspect, security server(s)secure communication served through wireless network platform 2410 toensure network's operation and data integrity in addition toauthorization and authentication procedures that CS gateway node(s) 2422and PS gateway node(s) 2418 can enact. Moreover, provisioning server(s)can provision services from external network(s) like networks operatedby a disparate service provider; for instance, WAN 2450 or GlobalPositioning System (GPS) network(s) (not shown). Provisioning server(s)can also provision coverage through networks associated to wirelessnetwork platform 2410 (e.g., deployed and operated by the same serviceprovider), such as the distributed antennas networks shown in FIG. 1(s)that enhance wireless service coverage by providing more networkcoverage. Repeater devices such as those shown in FIGS. 7, 8, and 9 alsoimprove network coverage in order to enhance subscriber serviceexperience by way of UE 2475.

It is to be noted that server(s) 2414 can comprise one or moreprocessors configured to confer at least in part the functionality ofmacro network platform 2410. To that end, the one or more processor canexecute code instructions stored in memory 2430, for example. It isshould be appreciated that server(s) 2414 can comprise a content manager2415, which operates in substantially the same manner as describedhereinbefore.

In example embodiment 2400, memory 2430 can store information related tooperation of wireless network platform 2410. Other operationalinformation can comprise provisioning information of mobile devicesserved through wireless platform network 2410, subscriber databases;application intelligence, pricing schemes, e.g., promotional rates,flat-rate programs, couponing campaigns; technical specification(s)consistent with telecommunication protocols for operation of disparateradio, or wireless, technology layers; and so forth. Memory 2430 canalso store information from at least one of telephony network(s) 2440,WAN 2450, enterprise network(s) 2470, or SS7 network 2460. In an aspect,memory 2430 can be, for example, accessed as part of a data storecomponent or as a remotely connected memory store.

In order to provide a context for the various aspects of the disclosedsubject matter, FIG. 24, and the following discussion, are intended toprovide a brief, general description of a suitable environment in whichthe various aspects of the disclosed subject matter can be implemented.While the subject matter has been described above in the general contextof computer-executable instructions of a computer program that runs on acomputer and/or computers, those skilled in the art will recognize thatthe disclosed subject matter also can be implemented in combination withother program modules. Generally, program modules comprise routines,programs, components, data structures, etc. that perform particulartasks and/or implement particular abstract data types.

FIG. 25 depicts an illustrative embodiment of a communication device2500. The communication device 2500 can serve as an illustrativeembodiment of devices such as mobile devices and in-building devicesreferred to by the subject disclosure (e.g., in FIGS. 15, 16A and 16B).

The communication device 2500 can comprise a wireline and/or wirelesstransceiver 2502 (herein transceiver 2502), a user interface (UI) 2504,a power supply 2514, a location receiver 2516, a motion sensor 2518, anorientation sensor 2520, and a controller 2506 for managing operationsthereof. The transceiver 2502 can support short-range or long-rangewireless access technologies such as Bluetooth®, ZigBee®, WiFi, DECT, orcellular communication technologies, just to mention a few (Bluetooth®and ZigBee® are trademarks registered by the Bluetooth® Special InterestGroup and the ZigBee® Alliance, respectively). Cellular technologies caninclude, for example, CDMA-1×, UMTS/HSDPA, GSM/GPRS, TDMA/EDGE, EV/DO,WiMAX, SDR, LTE, as well as other next generation wireless communicationtechnologies as they arise. The transceiver 2502 can also be adapted tosupport circuit-switched wireline access technologies (such as PSTN),packet-switched wireline access technologies (such as TCP/IP, VoIP,etc.), and combinations thereof.

The UI 2504 can include a depressible or touch-sensitive keypad 2508with a navigation mechanism such as a roller ball, a joystick, a mouse,or a navigation disk for manipulating operations of the communicationdevice 2500. The keypad 2508 can be an integral part of a housingassembly of the communication device 2500 or an independent deviceoperably coupled thereto by a tethered wireline interface (such as a USBcable) or a wireless interface supporting for example Bluetooth®. Thekeypad 2508 can represent a numeric keypad commonly used by phones,and/or a QWERTY keypad with alphanumeric keys. The UI 2504 can furtherinclude a display 2510 such as monochrome or color LCD (Liquid CrystalDisplay), OLED (Organic Light Emitting Diode) or other suitable displaytechnology for conveying images to an end user of the communicationdevice 2500. In an embodiment where the display 2510 is touch-sensitive,a portion or all of the keypad 2508 can be presented by way of thedisplay 2510 with navigation features.

The display 2510 can use touch screen technology to also serve as a userinterface for detecting user input. As a touch screen display, thecommunication device 2500 can be adapted to present a user interfacehaving graphical user interface (GUI) elements that can be selected by auser with a touch of a finger. The touch screen display 2510 can beequipped with capacitive, resistive or other forms of sensing technologyto detect how much surface area of a user's finger has been placed on aportion of the touch screen display. This sensing information can beused to control the manipulation of the GUI elements or other functionsof the user interface. The display 2510 can be an integral part of thehousing assembly of the communication device 2500 or an independentdevice communicatively coupled thereto by a tethered wireline interface(such as a cable) or a wireless interface.

The UI 2504 can also include an audio system 2512 that utilizes audiotechnology for conveying low volume audio (such as audio heard inproximity of a human ear) and high volume audio (such as speakerphonefor hands free operation). The audio system 2512 can further include amicrophone for receiving audible signals of an end user. The audiosystem 2512 can also be used for voice recognition applications. The UI2504 can further include an image sensor 2513 such as a charged coupleddevice (CCD) camera for capturing still or moving images.

The power supply 2514 can utilize common power management technologiessuch as replaceable and rechargeable batteries, supply regulationtechnologies, and/or charging system technologies for supplying energyto the components of the communication device 2500 to facilitatelong-range or short-range portable communications. Alternatively, or incombination, the charging system can utilize external power sources suchas DC power supplied over a physical interface such as a USB port orother suitable tethering technologies.

The location receiver 2516 can utilize location technology such as aglobal positioning system (GPS) receiver capable of assisted GPS foridentifying a location of the communication device 2500 based on signalsgenerated by a constellation of GPS satellites, which can be used forfacilitating location services such as navigation. The motion sensor2518 can utilize motion sensing technology such as an accelerometer, agyroscope, or other suitable motion sensing technology to detect motionof the communication device 2500 in three-dimensional space. Theorientation sensor 2520 can utilize orientation sensing technology suchas a magnetometer to detect the orientation of the communication device2500 (north, south, west, and east, as well as combined orientations indegrees, minutes, or other suitable orientation metrics).

The communication device 2500 can use the transceiver 2502 to alsodetermine a proximity to a cellular, WiFi, Bluetooth®, or other wirelessaccess points by sensing techniques such as utilizing a received signalstrength indicator (RSSI) and/or signal time of arrival (TOA) or time offlight (TOF) measurements. The controller 2506 can utilize computingtechnologies such as a microprocessor, a digital signal processor (DSP),programmable gate arrays, application specific integrated circuits,and/or a video processor with associated storage memory such as Flash,ROM, RAM, SRAM, DRAM or other storage technologies for executingcomputer instructions, controlling, and processing data supplied by theaforementioned components of the communication device 2500.

Other components not shown in FIG. 25 can be used in one or moreembodiments of the subject disclosure. For instance, the communicationdevice 2500 can include a slot for adding or removing an identity modulesuch as a Subscriber Identity Module (SIM) card or Universal IntegratedCircuit Card (UICC). SIM or UICC cards can be used for identifyingsubscriber services, executing programs, storing subscriber data, and soon.

In the subject specification, terms such as “store,” “storage,” “datastore,” data storage,” “database,” and substantially any otherinformation storage component relevant to operation and functionality ofa component, refer to “memory components,” or entities embodied in a“memory” or components comprising the memory. It will be appreciatedthat the memory components described herein can be either volatilememory or nonvolatile memory, or can comprise both volatile andnonvolatile memory, by way of illustration, and not limitation, volatilememory, non-volatile memory, disk storage, and memory storage. Further,nonvolatile memory can be included in read only memory (ROM),programmable ROM (PROM), electrically programmable ROM (EPROM),electrically erasable ROM (EEPROM), or flash memory. Volatile memory cancomprise random access memory (RAM), which acts as external cachememory. By way of illustration and not limitation, RAM is available inmany forms such as synchronous RAM (SRAM), dynamic RAM (DRAM),synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhancedSDRAM (ESDRAM), Synchlink DRAM (SLDRAM), and direct Rambus RAM (DRRAM).Additionally, the disclosed memory components of systems or methodsherein are intended to comprise, without being limited to comprising,these and any other suitable types of memory.

Moreover, it will be noted that the disclosed subject matter can bepracticed with other computer system configurations, comprisingsingle-processor or multiprocessor computer systems, mini-computingdevices, mainframe computers, as well as personal computers, hand-heldcomputing devices (e.g., PDA, phone, smartphone, watch, tabletcomputers, netbook computers, etc.), microprocessor-based orprogrammable consumer or industrial electronics, and the like. Theillustrated aspects can also be practiced in distributed computingenvironments where tasks are performed by remote processing devices thatare linked through a communications network; however, some if not allaspects of the subject disclosure can be practiced on stand-alonecomputers. In a distributed computing environment, program modules canbe located in both local and remote memory storage devices.

Some of the embodiments described herein can also employ artificialintelligence (AI) to facilitate automating one or more featuresdescribed herein. For example, artificial intelligence can be used inoptional training controller 230 evaluate and select candidatefrequencies, modulation schemes, MIMO modes, and/or guided wave modes inorder to maximize transfer efficiency. The embodiments (e.g., inconnection with automatically identifying acquired cell sites thatprovide a maximum value/benefit after addition to an existingcommunication network) can employ various AI-based schemes for carryingout various embodiments thereof. Moreover, the classifier can beemployed to determine a ranking or priority of the each cell site of theacquired network. A classifier is a function that maps an inputattribute vector, x=(x1, x2, x3, x4, . . . , xn), to a confidence thatthe input belongs to a class, that is, f(x)=confidence (class). Suchclassification can employ a probabilistic and/or statistical-basedanalysis (e.g., factoring into the analysis utilities and costs) toprognose or infer an action that a user desires to be automaticallyperformed. A support vector machine (SVM) is an example of a classifierthat can be employed. The SVM operates by finding a hypersurface in thespace of possible inputs, which the hypersurface attempts to split thetriggering criteria from the non-triggering events. Intuitively, thismakes the classification correct for testing data that is near, but notidentical to training data. Other directed and undirected modelclassification approaches comprise, e.g., naïve Bayes, Bayesiannetworks, decision trees, neural networks, fuzzy logic models, andprobabilistic classification models providing different patterns ofindependence can be employed. Classification as used herein also isinclusive of statistical regression that is utilized to develop modelsof priority.

As will be readily appreciated, one or more of the embodiments canemploy classifiers that are explicitly trained (e.g., via a generictraining data) as well as implicitly trained (e.g., via observing UEbehavior, operator preferences, historical information, receivingextrinsic information). For example, SVMs can be configured via alearning or training phase within a classifier constructor and featureselection module. Thus, the classifier(s) can be used to automaticallylearn and perform a number of functions, including but not limited todetermining according to a predetermined criteria which of the acquiredcell sites will benefit a maximum number of subscribers and/or which ofthe acquired cell sites will add minimum value to the existingcommunication network coverage, etc.

As used in some contexts in this application, in some embodiments, theterms “component,” “system” and the like are intended to refer to, orcomprise, a computer-related entity or an entity related to anoperational apparatus with one or more specific functionalities, whereinthe entity can be either hardware, a combination of hardware andsoftware, software, or software in execution. As an example, a componentmay be, but is not limited to being, a process running on a processor, aprocessor, an object, an executable, a thread of execution,computer-executable instructions, a program, and/or a computer. By wayof illustration and not limitation, both an application running on aserver and the server can be a component. One or more components mayreside within a process and/or thread of execution and a component maybe localized on one computer and/or distributed between two or morecomputers. In addition, these components can execute from variouscomputer readable media having various data structures stored thereon.The components may communicate via local and/or remote processes such asin accordance with a signal having one or more data packets (e.g., datafrom one component interacting with another component in a local system,distributed system, and/or across a network such as the Internet withother systems via the signal). As another example, a component can be anapparatus with specific functionality provided by mechanical partsoperated by electric or electronic circuitry, which is operated by asoftware or firmware application executed by a processor, wherein theprocessor can be internal or external to the apparatus and executes atleast a part of the software or firmware application. As yet anotherexample, a component can be an apparatus that provides specificfunctionality through electronic components without mechanical parts,the electronic components can comprise a processor therein to executesoftware or firmware that confers at least in part the functionality ofthe electronic components. While various components have beenillustrated as separate components, it will be appreciated that multiplecomponents can be implemented as a single component, or a singlecomponent can be implemented as multiple components, without departingfrom example embodiments.

Further, the various embodiments can be implemented as a method,apparatus or article of manufacture using standard programming and/orengineering techniques to produce software, firmware, hardware or anycombination thereof to control a computer to implement the disclosedsubject matter. The term “article of manufacture” as used herein isintended to encompass a computer program accessible from anycomputer-readable device or computer-readable storage/communicationsmedia. For example, computer readable storage media can include, but arenot limited to, magnetic storage devices (e.g., hard disk, floppy disk,magnetic strips), optical disks (e.g., compact disk (CD), digitalversatile disk (DVD)), smart cards, and flash memory devices (e.g.,card, stick, key drive). Of course, those skilled in the art willrecognize many modifications can be made to this configuration withoutdeparting from the scope or spirit of the various embodiments.

In addition, the words “example” and “exemplary” are used herein to meanserving as an instance or illustration. Any embodiment or designdescribed herein as “example” or “exemplary” is not necessarily to beconstrued as preferred or advantageous over other embodiments ordesigns. Rather, use of the word example or exemplary is intended topresent concepts in a concrete fashion. As used in this application, theterm “or” is intended to mean an inclusive “or” rather than an exclusive“or”. That is, unless specified otherwise or clear from context, “Xemploys A or B” is intended to mean any of the natural inclusivepermutations. That is, if X employs A; X employs B; or X employs both Aand B, then “X employs A or B” is satisfied under any of the foregoinginstances. In addition, the articles “a” and “an” as used in thisapplication and the appended claims should generally be construed tomean “one or more” unless specified otherwise or clear from context tobe directed to a singular form.

Moreover, terms such as “user equipment,” “mobile station,” “mobile,”subscriber station,” “access terminal,” “terminal,” “handset,” “mobiledevice” (and/or terms representing similar terminology) can refer to awireless device utilized by a subscriber or user of a wirelesscommunication service to receive or convey data, control, voice, video,sound, gaming or substantially any data-stream or signaling-stream. Theforegoing terms are utilized interchangeably herein and with referenceto the related drawings.

Furthermore, the terms “user,” “subscriber,” “customer,” “consumer” andthe like are employed interchangeably throughout, unless contextwarrants particular distinctions among the terms. It should beappreciated that such terms can refer to human entities or automatedcomponents supported through artificial intelligence (e.g., a capacityto make inference based, at least, on complex mathematical formalisms),which can provide simulated vision, sound recognition and so forth.

As employed herein, the term “processor” can refer to substantially anycomputing processing unit or device comprising, but not limited tocomprising, single-core processors; single-processors with softwaremultithread execution capability; multi-core processors; multi-coreprocessors with software multithread execution capability; multi-coreprocessors with hardware multithread technology; parallel platforms; andparallel platforms with distributed shared memory. Additionally, aprocessor can refer to an integrated circuit, an application specificintegrated circuit (ASIC), a digital signal processor (DSP), a fieldprogrammable gate array (FPGA), a programmable logic controller (PLC), acomplex programmable logic device (CPLD), a discrete gate or transistorlogic, discrete hardware components or any combination thereof designedto perform the functions described herein. Processors can exploitnano-scale architectures such as, but not limited to, molecular andquantum-dot based transistors, switches and gates, in order to optimizespace usage or enhance performance of user equipment. A processor canalso be implemented as a combination of computing processing units.

As used herein, terms such as “data storage,” data storage,” “database,”and substantially any other information storage component relevant tooperation and functionality of a component, refer to “memorycomponents,” or entities embodied in a “memory” or components comprisingthe memory. It will be appreciated that the memory components orcomputer-readable storage media, described herein can be either volatilememory or nonvolatile memory or can include both volatile andnonvolatile memory.

What has been described above includes mere examples of variousembodiments. It is, of course, not possible to describe everyconceivable combination of components or methodologies for purposes ofdescribing these examples, but one of ordinary skill in the art canrecognize that many further combinations and permutations of the presentembodiments are possible. Accordingly, the embodiments disclosed and/orclaimed herein are intended to embrace all such alterations,modifications and variations that fall within the spirit and scope ofthe appended claims. Furthermore, to the extent that the term “includes”is used in either the detailed description or the claims, such term isintended to be inclusive in a manner similar to the term “comprising” as“comprising” is interpreted when employed as a transitional word in aclaim.

In addition, a flow diagram may include a “start” and/or “continue”indication. The “start” and “continue” indications reflect that thesteps presented can optionally be incorporated in or otherwise used inconjunction with other routines. In this context, “start” indicates thebeginning of the first step presented and may be preceded by otheractivities not specifically shown. Further, the “continue” indicationreflects that the steps presented may be performed multiple times and/ormay be succeeded by other activities not specifically shown. Further,while a flow diagram indicates a particular ordering of steps, otherorderings are likewise possible provided that the principles ofcausality are maintained.

As may also be used herein, the term(s) “operably coupled to”, “coupledto”, and/or “coupling” includes direct coupling between items and/orindirect coupling between items via one or more intervening items. Suchitems and intervening items include, but are not limited to, junctions,communication paths, components, circuit elements, circuits, functionalblocks, and/or devices. As an example of indirect coupling, a signalconveyed from a first item to a second item may be modified by one ormore intervening items by modifying the form, nature or format ofinformation in a signal, while one or more elements of the informationin the signal are nevertheless conveyed in a manner than can berecognized by the second item. In a further example of indirectcoupling, an action in a first item can cause a reaction on the seconditem, as a result of actions and/or reactions in one or more interveningitems.

Although specific embodiments have been illustrated and describedherein, it should be appreciated that any arrangement which achieves thesame or similar purpose may be substituted for the embodiments describedor shown by the subject disclosure. The subject disclosure is intendedto cover any and all adaptations or variations of various embodiments.Combinations of the above embodiments, and other embodiments notspecifically described herein, can be used in the subject disclosure.For instance, one or more features from one or more embodiments can becombined with one or more features of one or more other embodiments. Inone or more embodiments, features that are positively recited can alsobe negatively recited and excluded from the embodiment with or withoutreplacement by another structural and/or functional feature. The stepsor functions described with respect to the embodiments of the subjectdisclosure can be performed in any order. The steps or functionsdescribed with respect to the embodiments of the subject disclosure canbe performed alone or in combination with other steps or functions ofthe subject disclosure, as well as from other embodiments or from othersteps that have not been described in the subject disclosure. Further,more than or less than all of the features described with respect to anembodiment can also be utilized.

What is claimed is:
 1. A waveguide system, comprising: a launcher thatfacilitates generation of electromagnetic waves; and a processor coupledto the launcher, wherein the processor facilitates performance ofoperations, comprising: obtaining one or more operational parameters forconfiguring the launcher to generate electromagnetic waves havingelectric fields that are not longitudinally aligned with an obstructiondisposed on an outer surface of a transmission medium and that extendoutside the obstruction, the electromagnetic waves having a cutofffrequency, and the cutoff frequency comprising a non-optical frequency;and directing the launcher to launch the electromagnetic waves accordingto the one or more operational parameters, and to induce theelectromagnetic waves on the outer surface of the transmission medium.2. The waveguide system of claim 1, wherein the launcher furthercomprises a waveguide structure for directing the electromagnetic wavesto the outer surface of the transmission medium.
 3. The waveguide systemof claim 1, wherein a substantial portion of the electric fields areapproximately perpendicular to the obstruction.
 4. The waveguide systemof claim 1, wherein the electromagnetic waves have a transverse wavemode.
 5. The waveguide system of claim 4, wherein the transverse wavemode comprises a transverse electric wave mode, a transverse magneticwave mode, a transverse electromagnetic wave mode, or any combinationsthereof.
 6. The waveguide system of claim 1, wherein the launchercomprises a slotted waveguide.
 7. The waveguide system of claim 1,wherein the launcher comprises a plurality of microwave circuits, eachhaving a radiating element.
 8. The waveguide system of claim 1, whereinthe obtaining comprises obtaining the one or more operational parametersfrom a look-up table, the look-up table comprising sets of operationalparameters for each of a plurality of electromagnetic waveformslaunchable by the launcher.
 9. The waveguide system of claim 1, whereinthe obstruction is disposed on the outer surface of the transmissionmedium at one portion of the transmission medium and not anotherdifferent portion of the transmission medium.
 10. The waveguide systemof claim 9, wherein the operations further comprise determining a typeof the obstruction on the outer surface of the transmission medium, andwherein the obtaining comprises obtaining the one or more operationalparameters according to the type of the obstruction.
 11. The waveguidesystem of claim 1, wherein the transmission medium does not comprise anoptical fiber for guiding the electromagnetic waves.
 12. The waveguidesystem of claim 1, wherein the electromagnetic waves experience lesspropagation losses at or near the cutoff frequency, and wherein thecutoff frequency is substantially greater than zero.
 13. The waveguidesystem of claim 1, wherein the outer surface of the transmission mediumcomprises an insulator.
 14. A method, comprising: determining, by awaveguide system, one or more operational parameters for generatingelectromagnetic waves having electric fields that are not polarizedlongitudinally in a first region above an outer surface of atransmission medium, and that extend into a second region located abovethe first region; generating, by the waveguide system, theelectromagnetic waves according to the one or more operationalparameters, the electromagnetic waves having a cutoff frequency; andinducing, by the waveguide system, the electromagnetic waves on theouter surface of the transmission medium.
 15. The method of claim 14,wherein the electric fields are approximately perpendicular to the firstregion above the outer surface of the transmission medium.
 16. Themethod of claim 14, wherein an obstruction is disposed on a portion ofthe outer surface of the transmission medium, and wherein theobstruction occupies the first region above the outer surface of thetransmission medium.
 17. The method of claim 14, wherein the outersurface of the transmission medium comprises a dielectric materialhaving a first dielectric constant, wherein the second region includes amaterial that has a second dielectric constant, and wherein the firstdielectric constant exceeds the second dielectric constant.
 18. Themethod of claim 17, wherein the material in the second region comprisesair.
 19. The method of claim 14, wherein the determining comprisesobtaining the one or more operational parameters from a look-up table,the look-up table comprising sets of operational parameters for each ofa plurality of launchable electromagnetic waveforms.
 20. A method,comprising: receiving, by a waveguide system, first electromagneticwaves on an outer surface of a transmission medium; detecting, by thewaveguide system, a degradation of a signal quality of the firstelectromagnetic waves due to first electric fields of the firstelectromagnetic waves inducing first currents in an obstruction disposedon the outer surface of the transmission medium; and generating, by thewaveguide system, second electromagnetic waves having second electricfields that induce second currents in the obstruction that are lower inmagnitude than the first currents, the electromagnetic waves having acutoff frequency.
 21. The method of claim 20, wherein the generating thesecond electromagnetic waves further results in the second electricfields extending in a region located above the obstruction.
 22. Themethod of claim 20, wherein the first electric fields induce the firstcurrents in the obstruction at least in part as a result of the firstelectric fields being aligned at least partially with a longitudinalcross-section of the obstruction.
 23. The method of claim 22, whereinthe second currents are lower in magnitude than the first currents atleast in part as a result of the second electric fields being lessaligned with the longitudinal cross-section of the obstruction than thefirst electric fields.
 24. The method of claim 20, wherein the firstelectric fields induce the first currents in the obstruction at least inpart as a result of the first electric fields having a first electricfield intensity in a longitudinal cross-section of the obstruction thatexceeds a second electric field intensity in a region outside theobstruction.
 25. The method of claim 20, wherein the second currents arelower in magnitude than the first currents at least in part as a resultof the second electric fields having a first electric field intensity ina region outside the obstruction that exceeds a second electric fieldintensity in a longitudinal cross-section of the obstruction.